STD Tuning Engine Om603 Low Compression

Om603 Low Compression

Om603 Low Compression

 
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av3ntador
OM603

13
06-07-2016, 03:56 PM #1
So I've done a compression test on my OM603 and I've found that it has low compression. Cylinder 1 has 160 PSI and cylinder 6 has 260 PSI, the rest are somewhere in between.

Now, what are my options? I still want to make this car a superturbodiesel build and make some serious power. 

I know I'd have to think about getting another engine or completely overhauling the current one. Overhauling it doesn't seem like such a bad idea to me. I wanted to put forged internals in it anyway. Anyone have any other suggestions?

'93 300SD - Project (Herlevi 8mm pump and HX40 coming)
'10 E350 - Daily  
av3ntador
06-07-2016, 03:56 PM #1

So I've done a compression test on my OM603 and I've found that it has low compression. Cylinder 1 has 160 PSI and cylinder 6 has 260 PSI, the rest are somewhere in between.

Now, what are my options? I still want to make this car a superturbodiesel build and make some serious power. 

I know I'd have to think about getting another engine or completely overhauling the current one. Overhauling it doesn't seem like such a bad idea to me. I wanted to put forged internals in it anyway. Anyone have any other suggestions?


'93 300SD - Project (Herlevi 8mm pump and HX40 coming)
'10 E350 - Daily  

starynovy
Holset

338
06-07-2016, 04:13 PM #2
Take it apart and decide. It can be cheap like leaking valves or expensive like worn out cylinders.

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Ex: 525tds 130kW, C250TD 160kW, E320CDI 200kW, ML400CDI 230kW, A6 R5TDI 130kW
Now: Q7 V8TDI 240kW, 320d 150kW, 335d 210kW
starynovy
06-07-2016, 04:13 PM #2

Take it apart and decide. It can be cheap like leaking valves or expensive like worn out cylinders.


-------------------------------------------------------------------------------------------------------------------------
Ex: 525tds 130kW, C250TD 160kW, E320CDI 200kW, ML400CDI 230kW, A6 R5TDI 130kW
Now: Q7 V8TDI 240kW, 320d 150kW, 335d 210kW

barrote
Superturbo

1,627
06-08-2016, 10:47 AM #3
use it til it dies ,
somewhere in the line it will go below 10bar and then start to smoke and misfire. then u need to rebuild it cause u can´t do nothing else ...
and by the way something is very wrong there, usually is the 6th cylinder wich starts to complain...
good luck whaever u decide.

FD,
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barrote
06-08-2016, 10:47 AM #3

use it til it dies ,
somewhere in the line it will go below 10bar and then start to smoke and misfire. then u need to rebuild it cause u can´t do nothing else ...
and by the way something is very wrong there, usually is the 6th cylinder wich starts to complain...
good luck whaever u decide.


FD,
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av3ntador
OM603

13
06-08-2016, 12:18 PM #4
(06-08-2016, 10:47 AM)barrote use it til it dies ,
somewhere in the line it will go below 10bar and then start to smoke and misfire. then u need to rebuild it cause u can´t do nothing else ...
and by the way something is very wrong there, usually is the 6th cylinder wich starts to complain...
good luck whaever u decide.

I found it weird too. According to the previous owner, the engine was rebuilt at 120k miles. Could it be because it has been sitting for 2 years? Maybe driving it might help the compression a bit, or will that make no difference? 

I think I might just rebuild/overhaul it with forged internals when I gather up enough cash. Then it'll be a real build. I'd probably put the 24 valve head on it and maybe even bore & stroke the block.

'93 300SD - Project (Herlevi 8mm pump and HX40 coming)
'10 E350 - Daily  
av3ntador
06-08-2016, 12:18 PM #4

(06-08-2016, 10:47 AM)barrote use it til it dies ,
somewhere in the line it will go below 10bar and then start to smoke and misfire. then u need to rebuild it cause u can´t do nothing else ...
and by the way something is very wrong there, usually is the 6th cylinder wich starts to complain...
good luck whaever u decide.

I found it weird too. According to the previous owner, the engine was rebuilt at 120k miles. Could it be because it has been sitting for 2 years? Maybe driving it might help the compression a bit, or will that make no difference? 

I think I might just rebuild/overhaul it with forged internals when I gather up enough cash. Then it'll be a real build. I'd probably put the 24 valve head on it and maybe even bore & stroke the block.


'93 300SD - Project (Herlevi 8mm pump and HX40 coming)
'10 E350 - Daily  

barrote
Superturbo

1,627
06-08-2016, 01:08 PM #5
the engine was stopped for 2 years ?
u have more than one problema with it , i´m afraid. the assle comes when after 30 years old stopping for 2 years and start after...
things like gaskets may not hold... erosion in the head , rust in metal parts like valves and seats, all those things......
my advice is still the same , use it til it breaks then have it rebuilt...
good luck.

FD,
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barrote
06-08-2016, 01:08 PM #5

the engine was stopped for 2 years ?
u have more than one problema with it , i´m afraid. the assle comes when after 30 years old stopping for 2 years and start after...
things like gaskets may not hold... erosion in the head , rust in metal parts like valves and seats, all those things......
my advice is still the same , use it til it breaks then have it rebuilt...
good luck.


FD,
Powered by tractor fuel

Tito
Holset

354
06-08-2016, 03:45 PM #6
Just drive it around. When a engine has sat for a long time give it some time to free some things. Like the valves not seating properly due to debris and dust. And when the piston is down in de cylinder the piston rings tend to lock in the piston because clearance is smaller down in de cylinder. A few revs from the starter wouldn't be much useful.
Tito
06-08-2016, 03:45 PM #6

Just drive it around. When a engine has sat for a long time give it some time to free some things. Like the valves not seating properly due to debris and dust. And when the piston is down in de cylinder the piston rings tend to lock in the piston because clearance is smaller down in de cylinder. A few revs from the starter wouldn't be much useful.

EvoPeter
GT2256V

161
06-20-2016, 05:17 PM #7
I spray some wd40 into the cylinders and let it work for 48h. It dissolves the soot between the piston rings and free them if they are stuck with to much soot. Have made difference in my engines when cold starting and bad compression.

I use 1 big bottle for one engine.
This post was last modified: 06-20-2016, 05:18 PM by EvoPeter.

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Mercedes 190 -92, om605 Stroker 2.75L, Dieselmeken 7,5mm (160cc) EDC with Baldur DSL1 ECU, Garrett GTX3576R A/R 1.06 without WG, SMF, 716.661 (SG-S370/6) Gearbox
EvoPeter
06-20-2016, 05:17 PM #7

I spray some wd40 into the cylinders and let it work for 48h. It dissolves the soot between the piston rings and free them if they are stuck with to much soot. Have made difference in my engines when cold starting and bad compression.

I use 1 big bottle for one engine.


-----------------------------------------------------------------------------------------------------------------------------
Mercedes 190 -92, om605 Stroker 2.75L, Dieselmeken 7,5mm (160cc) EDC with Baldur DSL1 ECU, Garrett GTX3576R A/R 1.06 without WG, SMF, 716.661 (SG-S370/6) Gearbox

 
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