rod knock or fueling issue?
rod knock or fueling issue?
I was cruising down the highway at about 3500ish rpms and it started making a knocking noise. When I initially pulled over, I couldn't hear any thing at idle(on the side of the highway), then after getting to the next exit I could hear it knocking under load and the rear main was leaking oil pretty bad. I limped it back home and over about 30 miles I lost a quart of oil(stopping to top off every now and then). There was no loss of power at any time.
After it sat for a couple days, I started the engine and it makes a knocking noise really loud for a couple of seconds and then quiets down substantially, almost to where you cant hear it unless you stomp on the gas pedal.
My delema is that the Mercedes specialty shop I got the engine from, said that it sounded like a fueling issue and not a rod knock just by description. One guy wants to take a look at it, but I already stripped most of the stuff from the block that I was going to put on another block I have. I'm not sure if I should put it back together and take it to them to see what they say, or just continue with swapping the blocks.
The guy that owns the shop and the employee that wants to look at it are not looking for my business. They were friends with my uncle that passed and just want to help me.
What do you guys think?
I had recently swapped a 617.952 into my 4runner and took it on its first trip. The engine had around 120k on it and I was told it was running excellent before the car was in an accident.
I was cruising down the highway at about 3500ish rpms and it started making a knocking noise. When I initially pulled over, I couldn't hear any thing at idle(on the side of the highway), then after getting to the next exit I could hear it knocking under load and the rear main was leaking oil pretty bad. I limped it back home and over about 30 miles I lost a quart of oil(stopping to top off every now and then). There was no loss of power at any time.
After it sat for a couple days, I started the engine and it makes a knocking noise really loud for a couple of seconds and then quiets down substantially, almost to where you cant hear it unless you stomp on the gas pedal.
My delema is that the Mercedes specialty shop I got the engine from, said that it sounded like a fueling issue and not a rod knock just by description. One guy wants to take a look at it, but I already stripped most of the stuff from the block that I was going to put on another block I have. I'm not sure if I should put it back together and take it to them to see what they say, or just continue with swapping the blocks.
The guy that owns the shop and the employee that wants to look at it are not looking for my business. They were friends with my uncle that passed and just want to help me.
What do you guys think?
Might have wiped a main. Mains knock under load, rods at first when the load is taken off. Once rods get real bad then they knock all the time, then maybe come out of the engine... What is your oil pressure when hot? bearings will lose oil pressure at idle when hot. If you change engines anyway I'd pull the pan and look at the old one just to find out.
I didn't mention that the engine I installed didn't have a flywheel/flex plate on it so I couldn't check to see if it was balanced or not. The extra block I have, I did take the flex plate and my toy flywheel down to get match balanced.
I don't know what the oil pressure is, but I do have a dummy light if there is none. I didn't lose pressure that I noticed. I'll pull the pan no matter what, if I keep that engine in service I still have to replace the rear main seal now.
I didn't mention that the engine I installed didn't have a flywheel/flex plate on it so I couldn't check to see if it was balanced or not. The extra block I have, I did take the flex plate and my toy flywheel down to get match balanced.
You have to take off the upper oil pan anyways and almost remove the crank to replace the rear main seal!
1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running
willbhere4u
07-21-2011, 09:25 AM #5I'd finish the swap and open up the ? bad engine and look at the mains and rod
You have to take off the upper oil pan anyways and almost remove the crank to replace the rear main seal!
1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running
I sort of had the same problem with my swap rig, the first doaner motor started nailing/ knocking. I replaced the injectors first, no change, then another comp ck and realized there was a clunk while cranking under compression on #5 but no noise cranking with the injector removed. At that time the comp # was down 100lbs, so I think the piston is cracked or something similar. My thought is the PO used eather to start and damaged the 5th cyl. I just picked up a 2nd motor and will pull this one apart when I get time. Probably too expensive to rebuild, but just curious what happened.
I think it will be better to just keep swapping the engines like I have already started. I'll be getting the injectors cleaned and tested and a valve adjustment before I start this one up.
Thanks for the replies.
I was talking to the mechanic at the shop I got the engines from and he said it sounds like the crank may have been hit when the car I got the engine from was in an accident. He said that's a definite crank killer on these engines. When I pulled the a/c pump and alternator brackets off originally, they were all bent. The a/c pump bolts were bent to the point they almost sheared off. I didn't see any marks on the crank pulley, but that doesn't mean it didn't make contact with the rest of the car.
I think it will be better to just keep swapping the engines like I have already started. I'll be getting the injectors cleaned and tested and a valve adjustment before I start this one up.
Thanks for the replies.
![[Image: 0806111041a.jpg]](http://i36.photobucket.com/albums/e16/me_tu05/4runner/0806111041a.jpg)
So I found this nice little clip in the bottom of the oil pan. Anyone know what its from? I have a feeling it is directly related to the knocking. Also, after removing the adapter plate, I found the oil leak was coming from the back of the head, and no, not the valve cover.
Shaft retainer,Poss.gear for oil pump chain shaft. Engine over heat at some time,Blown head gasket for oil return ,weak spot, be sure to check head for trueness if ever going to reuse,ck. block also. Usually oil leak gradually increases over long term, Po warmed up engine before driving,giving head time to warm up and expand ,sealing off leak.New owner starts ,takes off high speed,(lg. oil leak) now noticed, Mechanic ( blamed,for causing ). Also turbo feed tube can crack in this area.
As for the ring, I would guess its from the wrist pin, but I could be wrong.
The oil leak started when the knocking started. I inspected the oil feed line and there are no leaks in it, the oil was coming from the head/block interface. I don't know that I will ever use the block again, unless I have a need for a freshly rebuilt one.
As for the ring, I would guess its from the wrist pin, but I could be wrong.
1990 Power Ram 50 V6 SOHC 24V 6g72
I can be wrong, don't take everything I say as verbatim, please fact-check first.
My posts are my personal opinions and thoughts, unless otherwise noted.
It looks to be the clip that holds the oil pump chain tensioner on it's pin.
1990 Power Ram 50 V6 SOHC 24V 6g72
I can be wrong, don't take everything I say as verbatim, please fact-check first.
My posts are my personal opinions and thoughts, unless otherwise noted.
The sound is coming from the top front of the engine. I thought it was the injectors because it was also running a little rough. I did a diesel purge, changed the injector nozzles, and checked/adjusted the valves again. Still making the knock, but runs really smooth besides the knock. I even loosened each injector line one at a time to verify that it wasn't the injectors. I'm about to drive this thing into the ocean. Are there any other possibilities of what it could be?
I'm throwing around the idea of rebuilding the other engine in the hopes it doesn't need much to be a good dependable engine again (it only had 120K miles on it).
Bump this cuz my second engine sounds like its knocking. The sound is coming from the top front of the engine. I thought it was the injectors because it was also running a little rough. I did a diesel purge, changed the injector nozzles, and checked/adjusted the valves again. Still making the knock, but runs really smooth besides the knock. I even loosened each injector line one at a time to verify that it wasn't the injectors. I'm about to drive this thing into the ocean.
Are there any other possibilities of what it could be?
I'm throwing around the idea of rebuilding the other engine in the hopes it doesn't need much to be a good dependable engine again (it only had 120K miles on it).
1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running
willbhere4u
02-03-2012, 07:55 PM #13If it was a rod knock when you loosen the injector on the knocking cylinder it would stop knocking but same thing with a bad injector check out the vacuum pump
1987 300SDL 6spd manual om606.962 swap project
1985 300td euro 5spd wagon running
(02-03-2012, 09:47 PM)toyfreak Just to clarify, the sound changed when I loosened the lines but was still there.Try rigging a fuel can up to run the engine instead of using what is in the tank.If it doesn't make the sound, It may be a dodgy batch of fuel. Not unusual these days.
What am I supposed to look for on the vacuum pump?
your vacuum pump can be removed in few minutes, try pulling it off and running the engine for a few seconds without it.
(02-03-2012, 09:47 PM)toyfreak Just to clarify, the sound changed when I loosened the lines but was still there.Try rigging a fuel can up to run the engine instead of using what is in the tank.If it doesn't make the sound, It may be a dodgy batch of fuel. Not unusual these days.
What am I supposed to look for on the vacuum pump?
your vacuum pump can be removed in few minutes, try pulling it off and running the engine for a few seconds without it.
Could the IP be causing this knocking. I did recently start messing with the IP and it is pretty gutless in the upper rpms.
Also thinking that maybe these engines don't like extreme angles. It didn't start knocking until after my first wheeling trip with this engine......maybe I lost some oil pressure while climbing at weird angles and didn't notice it.
Definitely not the fuel, had the same noise with the diesel purge running into it and its had 3 different fuel fills since it started. I'll check the vac pump this weekend.
Could the IP be causing this knocking. I did recently start messing with the IP and it is pretty gutless in the upper rpms.
Also thinking that maybe these engines don't like extreme angles. It didn't start knocking until after my first wheeling trip with this engine......maybe I lost some oil pressure while climbing at weird angles and didn't notice it.
(02-04-2012, 04:26 AM)toyfreak Definitely not the fuel, had the same noise with the diesel purge running into it and its had 3 different fuel fills since it started. I'll check the vac pump this weekend.You dont have an oil guage but if i were in your shoes I would connect a guage ,even if it is just to check oil pressure at hot idle temporarily. It's an easy way to check bearing condition.
Could the IP be causing this knocking. I did recently start messing with the IP and it is pretty gutless in the upper rpms.
Also thinking that maybe these engines don't like extreme angles. It didn't start knocking until after my first wheeling trip with this engine......maybe I lost some oil pressure while climbing at weird angles and didn't notice it.
Also,I have found that if the bottom end is short on pressure,the cam will not be getting very much oil .it's easy to see if you look in the oil hole with it running at ilde, little to no oil flinging around means it isn't getting enough oil because of excess bearing clearance,worn out oil pump or very blocked filter.
Have you checked the combustion chambers for broken ball pins?
(02-04-2012, 04:26 AM)toyfreak Definitely not the fuel, had the same noise with the diesel purge running into it and its had 3 different fuel fills since it started. I'll check the vac pump this weekend.You dont have an oil guage but if i were in your shoes I would connect a guage ,even if it is just to check oil pressure at hot idle temporarily. It's an easy way to check bearing condition.
Could the IP be causing this knocking. I did recently start messing with the IP and it is pretty gutless in the upper rpms.
Also thinking that maybe these engines don't like extreme angles. It didn't start knocking until after my first wheeling trip with this engine......maybe I lost some oil pressure while climbing at weird angles and didn't notice it.
Also,I have found that if the bottom end is short on pressure,the cam will not be getting very much oil .it's easy to see if you look in the oil hole with it running at ilde, little to no oil flinging around means it isn't getting enough oil because of excess bearing clearance,worn out oil pump or very blocked filter.
Have you checked the combustion chambers for broken ball pins?
So, since I changed my oil from 15w40 to 5w40 mobile1 and a mobile 1 filter, I have had a up to 10 second delay for the oil pressure light to come on when starting the engine cold. I previously had a wix filter on and it was never longer than 1-2 seconds for the light to go off. I changed back to a wix filter and started it. No pressure according to the light. I could rev the engine and the light would start to dim, but never go off. This was over about 30 seconds. Tonight I just dropped the pan and checked to see if the oil pump was blocked, nothing.
I will probably try to fit the OEM filter housing on the engine next, but I don't really want to add oil and check for pressure and then have to drop it again to mess with the oil pump. Is there a way to check the pump itself without the engine running? I'll probably go get a cheap oil pressure gauge and install it before I start it again. I have the factory pressure sender connected to the oiling system, but I might have hooked it up to the wrong wire on the back of the instrument cluster. Probably try to fix that as well.
By ball pins, do you mean the ball I can see if I have the injectors out?
So, since I changed my oil from 15w40 to 5w40 mobile1 and a mobile 1 filter, I have had a up to 10 second delay for the oil pressure light to come on when starting the engine cold. I previously had a wix filter on and it was never longer than 1-2 seconds for the light to go off. I changed back to a wix filter and started it. No pressure according to the light. I could rev the engine and the light would start to dim, but never go off. This was over about 30 seconds. Tonight I just dropped the pan and checked to see if the oil pump was blocked, nothing.
I will probably try to fit the OEM filter housing on the engine next, but I don't really want to add oil and check for pressure and then have to drop it again to mess with the oil pump. Is there a way to check the pump itself without the engine running? I'll probably go get a cheap oil pressure gauge and install it before I start it again. I have the factory pressure sender connected to the oiling system, but I might have hooked it up to the wrong wire on the back of the instrument cluster. Probably try to fix that as well.
Also,drop number one bearing cap and have a look at the condition of the shell. If in doubt ,post a pic so we can have a look.
I don't like the use of mobil one in Any mercedes engine built before 1995. That rope seal in the rear will leak like a sieve as soon as mobil one hits it.
good luck...
While you have the pan off you can undo the pump and remove bottom of the oil pump and check the condition of the face plate. If there are round rings on the face plate from the gears,it's history.
Also,drop number one bearing cap and have a look at the condition of the shell. If in doubt ,post a pic so we can have a look.
I don't like the use of mobil one in Any mercedes engine built before 1995. That rope seal in the rear will leak like a sieve as soon as mobil one hits it.
good luck...
![[Image: IMG_0112.jpg]](http://i36.photobucket.com/albums/e16/me_tu05/4runner/IMG_0112.jpg)
regarding your earlier question,yes,the ball pins are those things you can see when the injectors are out.
I would pull the chambers and have a good look at them,especially the ball pins.
That oil pump doesn't look too bad to me. Are you sure the bearings are OK? I have seen a lot worse that registered zero pressure which was rectified by simply changing the pump.
regarding your earlier question,yes,the ball pins are those things you can see when the injectors are out.
I would pull the chambers and have a good look at them,especially the ball pins.
The chambers were the next thing I was going to look at. My cousin might have a puller in his dad's old tools.
I have an old timer telling me its a rod knock, but the first engine I put in my 4runner has all the main and rod bearings toasted and never sounded like this one. But who know, he might be right.
Thanks for your help RonB
I only checked the #1 bearing. Apparently, I have to pull the trans to take the upper pan off the engine since my trans adapter plate is bolted to the pan. I'm in the process of putting the OEM oil filter housing on the engine with a cheap pressure gauge. I have a feeling that my remote oil filter setup may have something to do with the oil pressure not building now. I'm not ordering a oil pump, they're $600 new. If I have to spend that much, I might as well swap a different engine in.
The chambers were the next thing I was going to look at. My cousin might have a puller in his dad's old tools.
I have an old timer telling me its a rod knock, but the first engine I put in my 4runner has all the main and rod bearings toasted and never sounded like this one. But who know, he might be right.
Thanks for your help RonB
If you are pulling your Combustion chambers, you can do another simple test , Grab the crank damper with both hands and rotate it to and fro .
If you can feel slackness you definitely have a bearing problem especially rod bearings. Rotate the engine and try it at different places to see which rod is knocking .
I have had loose dampers on mercedes engines which sounded just like worn main bearings ...
By doing this simple check I have saved customers a ton of money.
OK, I am sure your pump is good.
If you are pulling your Combustion chambers, you can do another simple test , Grab the crank damper with both hands and rotate it to and fro .
If you can feel slackness you definitely have a bearing problem especially rod bearings. Rotate the engine and try it at different places to see which rod is knocking .
I have had loose dampers on mercedes engines which sounded just like worn main bearings ...
By doing this simple check I have saved customers a ton of money.
I'm starting to think this may be a precup problem or maybe a piston wristpin problem. This engine is running so smooth right now, except for the knocking sound. I hope it's the precup and not internal damage.
Little update, I swapped back to the oe oil filter housing an got a cheap gauge to check pressure. It appears that I have great oil pressure. I also made a tool for taking the retaining nut out for the precups. I just have to find the tool to borrow to pull the actual precup now. I'll probably borrow my cousins scope too, just to check the piston condition.
I'm starting to think this may be a precup problem or maybe a piston wristpin problem. This engine is running so smooth right now, except for the knocking sound. I hope it's the precup and not internal damage.
I pulled the suspected precups and they look good. Don't really know what to look at now without dropping the trans to look at all the rod bearings. I am about to say fuck these engines and find something else to put in.
So, I have another question.......Could the timing chain tensioner being soft cause a knocking noise? Seems a little far fetched, but I know my tensioner can be easily pushed in with a screwdriver when I have the valve cover off.
I pulled the suspected precups and they look good. Don't really know what to look at now without dropping the trans to look at all the rod bearings. I am about to say fuck these engines and find something else to put in.
What did you do with the flywheel? How is it adapted to the trans?
If the tensioner is soft, turn the engine until the cam mark lines up with the mark on the first cam tower.
Then look at the damper .Where is the pointer on the front of the engine aimed at?
Did you grab the damper and give it a rotational jerk backwards and forwards? If a rod bearing is worn to any degree you will feel it.
What did you do with the flywheel? How is it adapted to the trans?
If the tensioner is soft, turn the engine until the cam mark lines up with the mark on the first cam tower.
Then look at the damper .Where is the pointer on the front of the engine aimed at?
The flywheel is adapted to the crank with a pressed in bushing spacer that centers the flywheel into the crank.
This is the first bushing I made
![[Image: 1223091800b.jpg]](http://i36.photobucket.com/albums/e16/me_tu05/4runner/1223091800b.jpg)
Installed on the engine
![[Image: 1230091406a.jpg]](http://i36.photobucket.com/albums/e16/me_tu05/4runner/1230091406a.jpg)
Thanks for your help RonB.
Yes, I can rotate the damper a small amount by hand. It has always been that way, but now it moves more than before. I think its a rod bearing or wrist pin in #3. You can hear it with a long screwdriver on the block. I'll probably run this engine for a little while and then dump it for something else.
The flywheel is adapted to the crank with a pressed in bushing spacer that centers the flywheel into the crank.
This is the first bushing I made
Installed on the engine
Thanks for your help RonB.
Before going further pull the crank pulleys off and make sure the hub is secure on the two dowel pins. I have seen mercedes dampers loose on the crank before and it only has to be a few thou of inch movement to make a knocking sound like a worn bearing.
Are you 100% sure the crank and flywheel are secure? With only three bolts you are asking a lot of them to hold the flywheel in place and a loose flywheel will knock .
Before going further pull the crank pulleys off and make sure the hub is secure on the two dowel pins. I have seen mercedes dampers loose on the crank before and it only has to be a few thou of inch movement to make a knocking sound like a worn bearing.
OK,check that hub for security and if that is OK then she has definitely damaged a bearing or wrist pin. The engine is in the car?Might be easier and cheaper to pull it out again and take the pan off and have good look. You maybe lucky and only need to replace the shells . In the worst case you could drop in the crank from the other engine .
Great. OK,check that hub for security and if that is OK then she has definitely damaged a bearing or wrist pin. The engine is in the car?Might be easier and cheaper to pull it out again and take the pan off and have good look. You maybe lucky and only need to replace the shells . In the worst case you could drop in the crank from the other engine .
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