Valve stem oil seals. Head off job?
Discussion
I've a 2004 VW Caddy (1996-2004 Mk4 Polo type) with the 1.9 SDI engine. Its always used some oil, I recently went swimming in it, it ingested some water, it coughed, spluttered and ran like a bag of s**t for a minute or two, I drove it 5 miles home, dried out the air filter and air box, then the next morning drove it 3 miles to have an oil and filter change.
Ever since the incident, it has a very lumpy idle when I start it in the morning, for about 10-15 seconds, starting is also accompanied by some smoke. It has used a litre of oil in less than two weeks! Also get some hesitation around 2200rpm, apart from that it runs fine.
Using my limited mechanical skills, I'm thinking the valve stem oil seals are shot, leaking oil into the cylinder overnight and causing the smoke and dodgy cold idle?
Anything else it could be, anyway of confirming/ disproving this? Could taking water in through the intake have damaged them?
If it is the valve stem seals, can they be changed with the head on, obviously the camshaft would need removing.
Or have I likely damaged the piston rings or head gasket?
Yes, I know I'm a knob, but by the time I saw the huuuge puddle/flood it was too late!
Ever since the incident, it has a very lumpy idle when I start it in the morning, for about 10-15 seconds, starting is also accompanied by some smoke. It has used a litre of oil in less than two weeks! Also get some hesitation around 2200rpm, apart from that it runs fine.
Using my limited mechanical skills, I'm thinking the valve stem oil seals are shot, leaking oil into the cylinder overnight and causing the smoke and dodgy cold idle?
Anything else it could be, anyway of confirming/ disproving this? Could taking water in through the intake have damaged them?
If it is the valve stem seals, can they be changed with the head on, obviously the camshaft would need removing.
Or have I likely damaged the piston rings or head gasket?
Yes, I know I'm a knob, but by the time I saw the huuuge puddle/flood it was too late!
It sounds like you've got a pretty serious oil consumption problem, if it's as bad as it sounds you should be able to see some evidence of oil seeping into the cylinder after a decent cold stay.
For changing the seals there shouldn't be a reason you can't leave the head in-situ - turn each cylinder to TDC before you remove anything and it'll stop the valves dropping out without chance of rescue.
For changing the seals there shouldn't be a reason you can't leave the head in-situ - turn each cylinder to TDC before you remove anything and it'll stop the valves dropping out without chance of rescue.
The fact it ingested some water and now doesnt run properly, means you've well f
ked it.
And it sure as hell will be nothing to do with valve stem oil seals.
As to what damage you have done...could be anything from bent conrods, damaged pistons, or who knows what. Water inside engines rarely ends well.
ked it.And it sure as hell will be nothing to do with valve stem oil seals.
As to what damage you have done...could be anything from bent conrods, damaged pistons, or who knows what. Water inside engines rarely ends well.
Surely if I'd bent something it would run rough regardless of temperature?
I did it three weeks ago and have over 1000 miles since, besides the rough idle for 10 seconds when cold and the slight hesitation, it runs perfectly, smooth and sounds healthy (as smooth and healthy sounding as an ancient NA diesel can be!).
The hesitation only happens when I feather the power around 2200 RPM, it is very slight and isn't as bad as it used to be, if I accelerate past that point it doesn't happen.
I know full well the cause of water ingestion, I bent a conrod on my first car in this manner, difference being I purposely drove through the flood then, this time it was dark, the water was still and I didn't realise I'd hit it until I was halfway through it!
Is it possible to have bent something, but it still run normally (bar the lumpy cold idle and slight, barely noticeable hesitation?)
I did it three weeks ago and have over 1000 miles since, besides the rough idle for 10 seconds when cold and the slight hesitation, it runs perfectly, smooth and sounds healthy (as smooth and healthy sounding as an ancient NA diesel can be!).
The hesitation only happens when I feather the power around 2200 RPM, it is very slight and isn't as bad as it used to be, if I accelerate past that point it doesn't happen.
I know full well the cause of water ingestion, I bent a conrod on my first car in this manner, difference being I purposely drove through the flood then, this time it was dark, the water was still and I didn't realise I'd hit it until I was halfway through it!
Is it possible to have bent something, but it still run normally (bar the lumpy cold idle and slight, barely noticeable hesitation?)
Rickyy said:
Is it possible to have bent something, but it still run normally (bar the lumpy cold idle and slight, barely noticeable hesitation?)
yes it is perfectly possible. I had a 3.0 V6 peugoet with 1 bent rod and it still went like a rocket. i only paid £100 for it so just drove it until it blew up.I cant think of a mechanical reason that would cause damage to your valve stem oil seals due to water ingress.
That area is not subject to pressure stresses and because water was ingested then minor combustion chamber damage, rods, rings, pistons, valves, etc is more likely, dont you think?
Also, don't rule out some ongoing (and variable) problems with ignition, like condensation inside the cap, or damp around the ignition amplifier.
Dirty water can upset any ignition system big time but may also lead to longer term external sparking as a result of residual carbon tracking, perhaps easy to observe on a dark night with the engine running.
I would advise a thorough clean of ALL ignition components and check the cylinder compression as already mentioned.
Less likely but still possible, I am thinking of an injection engine with a few water sensitive components in the engine bay, AFM, throttle pot, sensors and all the local wiring. Also, where is the ECU and did it get wet?
Do you have any way of referring to a test manual for these components?
That area is not subject to pressure stresses and because water was ingested then minor combustion chamber damage, rods, rings, pistons, valves, etc is more likely, dont you think?
Also, don't rule out some ongoing (and variable) problems with ignition, like condensation inside the cap, or damp around the ignition amplifier.
Dirty water can upset any ignition system big time but may also lead to longer term external sparking as a result of residual carbon tracking, perhaps easy to observe on a dark night with the engine running.
I would advise a thorough clean of ALL ignition components and check the cylinder compression as already mentioned.
Less likely but still possible, I am thinking of an injection engine with a few water sensitive components in the engine bay, AFM, throttle pot, sensors and all the local wiring. Also, where is the ECU and did it get wet?
Do you have any way of referring to a test manual for these components?
Edited by honestjohntoo on Saturday 6th April 10:54
honestjohntoo said:
I cant think of a mechanical reason that would cause damage to your valve stem oil seals due to water ingress.
That area is not subject to pressure stresses and because water was ingested then minor combustion chamber damage, rods, rings, pistons, valves, etc is more likely, dont you think?
Also, don't rule out some ongoing (and variable) problems with ignition, like condensation inside the cap, or damp around the ignition amplifier.
Dirty water can upset any ignition system big time but may also lead to longer term external sparking as a result of residual carbon tracking, perhaps easy to observe on a dark night with the engine running.
I would advise a thorough clean of ALL ignition components and check the cylinder compression as already mentioned.
Less likely but still possible, I am thinking of an injection engine with a few water sensitive components in the engine bay, AFM, throttle pot, sensors and all the local wiring. Also, where is the ECU and did it get wet?
Do you have any way of referring to a test manual for these components?
ignition components....in a diesel..That area is not subject to pressure stresses and because water was ingested then minor combustion chamber damage, rods, rings, pistons, valves, etc is more likely, dont you think?
Also, don't rule out some ongoing (and variable) problems with ignition, like condensation inside the cap, or damp around the ignition amplifier.
Dirty water can upset any ignition system big time but may also lead to longer term external sparking as a result of residual carbon tracking, perhaps easy to observe on a dark night with the engine running.
I would advise a thorough clean of ALL ignition components and check the cylinder compression as already mentioned.
Less likely but still possible, I am thinking of an injection engine with a few water sensitive components in the engine bay, AFM, throttle pot, sensors and all the local wiring. Also, where is the ECU and did it get wet?
Do you have any way of referring to a test manual for these components?
Edited by honestjohntoo on Saturday 6th April 10:54
jimbob82 said:
I do it myself sometimes, doesn't quite register even though it's in the OP, and I ask the question diesel or petrol, 
Yeah! Sorry about that! Shhit happens, got my diagnostics in gear before engaging the brain.

Mind you, anyone looking for a similar problem on a petrol car, after all these floods, can follow the logic!

honestjohntoo said:
I cant think of a mechanical reason that would cause damage to your valve stem oil seals due to water ingress.
That area is not subject to pressure stresses and because water was ingested then minor combustion chamber damage, rods, rings, pistons, valves, etc is more likely, dont you think?
Also, don't rule out some ongoing (and variable) problems with ignition, like condensation inside the cap, or damp around the ignition amplifier.
Dirty water can upset any ignition system big time but may also lead to longer term external sparking as a result of residual carbon tracking, perhaps easy to observe on a dark night with the engine running.
I would advise a thorough clean of ALL ignition components and check the cylinder compression as already mentioned.
Less likely but still possible, I am thinking of an injection engine with a few water sensitive components in the engine bay, AFM, throttle pot, sensors and all the local wiring. Also, where is the ECU and did it get wet?
Do you have any way of referring to a test manual for these components?
I'm by no means an expert, just have a very basic grasp of engines! I've honestly no idea whether valve stem seals could be damaged in this way or not. Just trying to use logic, smoke on start up followed by a lumpy idle, thought that could be down to oil seeping into the cylinders overnight.That area is not subject to pressure stresses and because water was ingested then minor combustion chamber damage, rods, rings, pistons, valves, etc is more likely, dont you think?
Also, don't rule out some ongoing (and variable) problems with ignition, like condensation inside the cap, or damp around the ignition amplifier.
Dirty water can upset any ignition system big time but may also lead to longer term external sparking as a result of residual carbon tracking, perhaps easy to observe on a dark night with the engine running.
I would advise a thorough clean of ALL ignition components and check the cylinder compression as already mentioned.
Less likely but still possible, I am thinking of an injection engine with a few water sensitive components in the engine bay, AFM, throttle pot, sensors and all the local wiring. Also, where is the ECU and did it get wet?
Do you have any way of referring to a test manual for these components?
Edited by honestjohntoo on Saturday 6th April 10:54
I'm not too sure if it is using as much oil as I thought, as I said it had an oil change the morning after and a week and a half afterwards it was below the minimum mark. I had it topped up last week, I checked it today and it has barely moved. I'm beginning to wonder if it was under filled the first time.
Just going to keep my eye on it, I'm saving for a new van as I've outgrown this one anyway. Engines are around £200 on ebay, I'll take it off the road and stick a second hand lump in.
Thanks to everyone for your input

It's far more likely you have cracked a piston or broken the rings lands and/or rings. This is a very common failure on a diesel after ingesting water, and ties in with the oil consumption and starting problems. Low compression really makes itself known when starting, since the engine is turned over slowly so the compression has time to leak away, and any injected fuel goes straight out of the exhaust as white smoke.
Once running the higher piston speeds and reduce clearances as the pistons heat up improves the situation a little so it can actually fire on that cylinder.
Once running the higher piston speeds and reduce clearances as the pistons heat up improves the situation a little so it can actually fire on that cylinder.
Makes sense! The symptoms have pretty much vanished now, the calm before the storm? The hesitation has gone completely, the rough idle is still there, but for a second or two now. It used to be a bit rough on really cold mornings before I dunked it anyway.
I'm just going to run it until it dies, replacement engines are on Ebay for around £200.
I'm just going to run it until it dies, replacement engines are on Ebay for around £200.
Gassing Station | Engines & Drivetrain | Top of Page | What's New | My Stuff



