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Low compression in all four cylinders

Tiny
MDNELSON00
  • MEMBER
  • 2012 VOLKSWAGEN GTI
  • 2.0L
  • 4 CYL
  • 2WD
  • MANUAL
  • 95,000 MILES
Hi, I'm new here.

I have the car listed above with low compression across all 4 cylinders.

#1 - 110
#2 - 110
#3 - 115
#4 - 115

Leak down results are as follows:

#1 - 5%
#2 - 6%
#3 - 5%
#4 - 7%

All tests were run by a reputable non-dealer mechanic that specializes in German cars. The car starts fine and runs smoothly under moderate power. They media blasted the valves and replaced the fuel injectors (the symptoms that brought the car into the shop were rough running on startup and a check engine light- the fuel injectors fixed both issues).

So, my question is this: Is it possible that this car will run reasonably well for the next few years, given proper maintenance? Or should I get rid of it ASAP? My wife would like to replace her 2006 Toyota Corolla (180,000 miles), so I would prefer to keep my car if it will run relatively well for a few years.

Thanks in advance for your thoughts.

Edit: The shop I took it to thinks the problem is in the bottom end of the engine, and that the engine should be replaced at a cost of between $8,000.00 and $14,000.
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Monday, May 11th, 2020 AT 12:16 PM

11 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Good afternoon,

Low compression on all cylinders tells me you may have a valve timing issue.

What I mean is the chain may be worn and the marks are no longer in sync.

Has anyone remove the front cover to be sure the timing is correct?

Roy

Valve Timing, Checking

Special tools, testers and auxiliary items required

Dial Gauge 0-10 mm (VAS 6079)

Dial Gauge Adapter (T10170) or Dial Gauge Adapter (T10170 A)

Caliper Gauge

Remove the upper timing chain cover. Refer to => [ Upper Timing Chain Cover ].

Rotate the crankshaft from above, using the vibration damper bolt and the socket SW 24, in engine rotation direction until the marks - arrows - are almost on top.

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Remove the spark plug from cylinder 1.

Install the Dial Gauge Adapter (T10170/A) all the way into the spark plug threads.

ImageOpen In New TabZoom/Print

Insert the Dial Gauge 0-10 mm (VAS 6079) with the Extending Piece (T10170A/1) all the way and secure it with the locking nut - arrow -.

Rotate the crankshaft slowly to the maximum dial reading in engine rotation direction. When the maximum dial reading has reached Bottom Dead Center (BDC) of the gauge, the piston is at Top Dead Center (TDC).

If the crankshaft was turned past TDC, turn the crankshaft two more turns in engine rotation direction. Do not turn the engine in the opposite direction of engine rotation.

Measure the distance from the left outer edge - A - to the mark - B - on the intake camshaft.

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Specified value: 61 to 64 mm.

Once the specified value is reached, measure the distance between the mark on the intake camshaft - B - and the mark on the exhaust camshaft - C -.

ImageOpen In New TabZoom/Print

Specified value: 124 to 126 mm

If one tooth has an offset, there will be a deviation of approximately 6 mm from the specified value. Install the timing chain once again if there is an offset.
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Monday, May 11th, 2020 AT 1:49 PM
Tiny
STEVE W.
  • MECHANIC
  • 13,452 POSTS
Did they also do a wet compression test, where they put some oil into each cylinder and see if the compression goes up? If the readings you have are dry readings and adding oil makes it rise then it is likely the piston rings or wear in the cylinder bore. The wet compression numbers would tell you more. VW shows that new it should have 160-203 psi with a wear limit of 101 psi. So yours is a worn engine that appears to have worn evenly. Rebuild or replace are the primary options for engines. It comes down to what the rest of the vehicle is like, if it's in good shape and you like it, pick an option. If it has other problems or is rusting out then you might want to replace the entire car.
Depending on where you are you might want to look on car-part. Com and see what you can find in a used engine. The ones I find run between $2,000.00 to $3,000 with a 90 day warranty.
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Monday, May 11th, 2020 AT 1:50 PM
Tiny
MDNELSON00
  • MEMBER
  • 5 POSTS
Hi Roy,

Thanks very much for the reply. I will call the shop and see if they checked this- there is a known issue with the (plastic) timing chain tensioner (and an extended warranty for it), so perhaps I should have the dealer check it.

Mike
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Monday, May 11th, 2020 AT 1:53 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
I agree. It may be that simple.

Roy
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Monday, May 11th, 2020 AT 1:55 PM
Tiny
MDNELSON00
  • MEMBER
  • 5 POSTS
Hi Steve and Roy-

I just talked with the shop and they didn't run a wet compression test, as they did it when the car was warm. They also don't think it's a timing issue because that would cause a code to be thrown, and it's been clear since the fuel injectors were done. They think it might be a stuck ring. If the cylinder sleeves are okay, a ring job would be about $4,500.00. The rest of the car is in good shape. I haven't driven it hard at all (still on the original brakes!).
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Monday, May 11th, 2020 AT 2:16 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
I disagree. That would mean that all the rings are an issue.

Roy
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Monday, May 11th, 2020 AT 2:46 PM
Tiny
STEVE W.
  • MECHANIC
  • 13,452 POSTS
I could see a stuck ring in one or two cylinders but not in all 4. Timing issues are possible without setting a code if the amount is still withing the code setting limits. It doesn't take much of a valve timing issue to drop a few pounds of compression.
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Monday, May 11th, 2020 AT 2:53 PM
Tiny
MDNELSON00
  • MEMBER
  • 5 POSTS
Roy and Steve, I see your point. I am waiting on a call back from the VW dealership to see about getting the timing checked. Thank you!
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Monday, May 11th, 2020 AT 3:17 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Keep us updated.

Roy
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Monday, May 11th, 2020 AT 3:23 PM
Tiny
MDNELSON00
  • MEMBER
  • 5 POSTS
I just got it back from the dealer and the timing is correct, and the timing chain and tensioner do not need to be replaced. They also ran a compression check and got 145 in all 4 cylinders. It's much better but still 5 below spec. I'm just going to drive it and make sure I get the oil changed every 5,000 miles. Thanks for all the help, I appreciate it!

Mike
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Friday, May 15th, 2020 AT 4:03 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
You are welcome.

Always glad to help.

Roy
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Friday, May 15th, 2020 AT 4:07 PM

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