Broken piston rings or something else?

[sphere]

EDIT:
Car is GTI 2006 DSG with 85k on the clock.

I had been noticing on occasion the car would rev itself in idle and sound a little rough. Everyday driving was otherwise fine, seemed normal. Engine light came on a day or so after, so I took it in to get looked at. All codes were cleared and I drove back to get it checked again.

These were the errors thrown back:

Leak in Air Intake System P2279
Lower Limit Reached

Bank 1; System too Lean at Idle
P2187 No Signal/No Communication

Idle Control System RPM Higher than Expected.
P0507 Upper Limit Reached Intermittent


I did a bit of research into it myself and it all seemed to suggest a vacuum leak and possible need for a new PCV valve. I pulled the oil dipstick with the engine running and there was definitely suction and the engine was rough with it out.

Anyhow, after a day at the workshop I was told that it's no issue with valves or the like but broken piston rings causing the issue. I was shown some pressure gauge hooked up which indicated little pressure from the cylinders. Was told that either I'd need to replace the engine with another or get the current one reconditioned - both which will cost a fortune.

Has anyone else had this problem and should I get a second opinion (that alone will cost a lot)? Looking for some advice from those who have had experience with this sort of thing before.

Thanks

[gldgti]

I would get a second opinion.... BUT also -

Tell us what car
Tell us what engine
Tell us how many km

We are not psychics!

[GTI4ME]

Definately get a second opinion.
However, did you get any info regarding the (im assuming) compression test? What were the figures per cylinder? In 6 years im yet to even hear of a mk5 GTI engine drop a cylinder, not to say it doesnt/couldnt happen but its pretty left field. The PCV would definately have gotten my vote first.
An engine rebuild would normally be a worst case scenario so a second opinion would almost be a must, especially given that during daily operation the engine seems fine.
Good luck, keep us updated with the outcome.

[sphere]

Definately get a second opinion.
However, did you get any info regarding the (im assuming) compression test?

Don't have the results written down, but was shown the pressure gauge on the cylinders and the needle was showing next to nothing. Then the guy switched to a good cylinder and the needle went up into red.

There is really no noticeable loss of power when driving either (if this would be a symptom).

I'm definitely going to get a second opinion on this. I am not completely convinced it's the piston rings, but who knows until I get it poked and prodded some more.

[wai]

There are a number of things that could give a low compression reading.

The intake could be obstructed; easy to check out and clear.

A valve could have bent or the seat or valve burnt; this would be seen with the rocker cover off and see if a valve is not operating correctly.

The rings could have failed; this would also mean a lot of blow by gasses, and you would be getting horrible piston slap. You would also see metal particles in the sump oil.

The head gasket could have failed between adjacent cylinders; would be revealed by low compression in adjacent cylinders and normal compression in the rest.

The head gasket could have failed into an oil gallery or water jacket; you would see contamination of the oil/water.

Whatever it is, it will need checking and will probably be expensive.

[Ben J]

Re: Broken piston rings or something else?

If a cylinder had no compression you'd definitely notice a difference in power and it would run like **** all the time.. This doesn't make much sense. I'd definitely get a second opinion

Sent from my GT-I9305T using Tapatalk 2

[lankfert]

As Ben said. If there was a knackered piston, the car would run like crap and barely idle if at all.

Go elsewhere.

[sphere]

As Ben said. If there was a knackered piston, the car would run like crap and barely idle if at all.

Go elsewhere.

Ok, thanks for that info. Even with a couple of rings busted it would run like crap? There's really no difference when driving, it's only when it's sitting idle in P and sometimes stopped at lights. I'll definitely be getting it checked elsewhere anyhow.

[h100vw]

This needs a leak down check to see where the compression has gone. You set the cylinder to tdc so the valves are closed then, connect a pressurised air source to a sparkplug adapter. Hunt down the leak if any. Rings/piston, it'll be coming out of the dipstick/oil filler. If there's a bad valve either the exhaust or inlet. Head gasket, coolant bottle.

If you can drive the car and assess the power as normal, I'd be surprised if it's any of the above. If your car lost 50hp you would notice.

Gavin

[brad]

Are you getting this opinion from a specialist VW workshop or a generalist light vehicle workshop?

What part of Sydney are you in?


Symptoms & fault codes all point to a vacuum leak or similar. Possibly an inlet valve issue but that's a long shot.

[sphere]

Are you getting this opinion from a specialist VW workshop or a generalist light vehicle workshop?

What part of Sydney are you in?


Symptoms & fault codes all point to a vacuum leak or similar. Possibly an inlet valve issue but that's a long shot.

Was just from a local generalist workshop as I thought it'd be a quick valve fix and I'd be on my way.

I'm in north-west Sydney.

[sphere]

Unplugged the pcv hose pipe then plugged the whole with a thumb and the car idle was smoother with little to no suction from dipstick when pulled out. With the pcv hose pipe in you can hear a little hiss just after engine is switched off for about 10 seconds, but if you pull out the dipstick the hiss stops straight away. Also, the oil filler cap is sucked on very tightly with engine running. Can take it off, but need a lot of effort.