Help analysing cylinder compression results

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mastersdave2

New Member
Posts
86
Location
Birmingham
Ok cant afford to replace my engine, probably just about afford to repair it, but here goes, i have posted on this same problem before, and i think im edging closer to a diagnosis.

conducted a compression test today whilst engine still warm.

in piston 1 (closest to rad) reading was 413 psi
in piston 2 reading was 419 psi
in piston 3 reading was 414 psi
in piston 4 reading was 461 psi

is it a coincidence that i replaced my head gasket in January, after driving around for around 6 weeks thinking the hissing noise was my exhaust gasket, when it turned out that my head gasket was leaking compression gas from piston 4 out the back of the block?

the symptoms i have had since changing my head gasket in jan are as follows:

when over worked either on heavy loads or long runs, when i drop to idle tick over the oil light flickers (i have changed oil pressure switch and oil pressure relief valve, oil change and filter)

if when over worked and the oil light flickers, i shut down the engine, it is very stiff in turning over, almost like i got a flat battery very slow turn over, this is usually exclusive to when the engine is very hot.

on cold starts it is very smokey until it is warmed up

high fuel consumption

runs rough and is very lumpy

its a 300tdi with 205k miles on the clock.

please somebody give me some advise that i can work with, im not afraid to get my hands dirty, just need some know how, can someone please explain to me what they think is going on.
 
hi as for the start up smoke is it blue if not let me know plus does it smoke when driving if so what colour is it.
slow starting when warm could be oil or water leaking into the cylenders.
ill also and the light might be low oil presure
 
Ok cant afford to replace my engine, probably just about afford to repair it, but here goes, i have posted on this same problem before, and i think im edging closer to a diagnosis.

conducted a compression test today whilst engine still warm.

in piston 1 (closest to rad) reading was 413 psi
in piston 2 reading was 419 psi
in piston 3 reading was 414 psi
in piston 4 reading was 461 psi

is it a coincidence that i replaced my head gasket in January, after driving around for around 6 weeks thinking the hissing noise was my exhaust gasket, when it turned out that my head gasket was leaking compression gas from piston 4 out the back of the block?

the symptoms i have had since changing my head gasket in jan are as follows:

when over worked either on heavy loads or long runs, when i drop to idle tick over the oil light flickers (i have changed oil pressure switch and oil pressure relief valve, oil change and filter)

if when over worked and the oil light flickers, i shut down the engine, it is very stiff in turning over, almost like i got a flat battery very slow turn over, this is usually exclusive to when the engine is very hot.

on cold starts it is very smokey until it is warmed up

high fuel consumption

runs rough and is very lumpy

its a 300tdi with 205k miles on the clock.

please somebody give me some advise that i can work with, im not afraid to get my hands dirty, just need some know how, can someone please explain to me what they think is going on.
how hot did it get previous head gasket change ?too hot oil can damage bearing shells ,pistons can pick up on bores, or could just be old age
 
sorry, yes blue smoke, it smokes right up until it reaches normal temperatures, maybe 5- 10 mins of running, 2 or 3 miles, after that no smoke.

im assuming, that low oil pressure is either the pump? oil getting too hot and not passing through pump properly?

is there a link between all of the issues i have, my theory is that, my 4th piston is glazed, preventing oil lubricating the piston correctly, the oil over heats causing my oil pressure to drop, the the stiffness is because the 4th piston is seizing on the bore walls (metal expands when hot) thats the only logical way i can see of having all the issues, but im no mechanic thats why im hoping all you enthusiasts out there can shed some light on it
 
how hot did it get previous head gasket change ?too hot oil can damage bearing shells ,pistons can pick up on bores, or could just be old age

not very hot, at the time we had all that snow, i only went out in the disco to have a bit of fun, wasn't worked hard, low revs everywhere when it snowed, no sign of shells wearing, nothing in the oil anyway.
 
low oil pressure is either pump or crank bearings ,cam bearings or oil squirts have fallen off,glazed bores cause oil use, pistons cooled by oil squirt
 
seen as i have compression, im presuming the best course of action (other than replacement engine) is to strip the block down, re-hone the glazed bore, new set of piston rings (would it be worth replacing all 4 sets of piston rings?), new main bearings, new crank bearings, might as well get a set of gaskets for block, is it worth getting some new oil pump gears whilst im at it?? or does anyone have any other suggestions?
 
i would fit a second hand unit one you can hear/see running,mot failures are very cheap will be cheaper than a rebuild for sure 205k is going to need lots of work once you start stripping it imho
 
seen as i have compression, im presuming the best course of action (other than replacement engine) is to strip the block down, re-hone the glazed bore, new set of piston rings (would it be worth replacing all 4 sets of piston rings?), new main bearings, new crank bearings, might as well get a set of gaskets for block, is it worth getting some new oil pump gears whilst im at it?? or does anyone have any other suggestions?

you need to have a look to start with ,shells can easily be looked at with sump off,top shell on conrod will be worst if worn and bottom main bearing ,oil squirts can be checked at the same time , youd need to measure bores to see if re-ringing and hone is viable ,smoke on start up may well be valve stem seals or turbo passing more oil than it should ,you can check by removing hose from turbo to intercooler,see what drips out with engine running or not ,and by removing hose to inlet manifold and seeing if it effects cold running, is one cylinder oily others not ,tappets set correctly etc ,you may have several issues
 
DON'T USE BRITPART for an engine rebuild i had a wheel bearing that went after 1000 miles and the second one after 1500 miles please dont use them.
also are you useing oil at all or water.
 
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