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AudiTurbo
06-04-2013, 04:04 AM
So, I have 157K miles on my car and when I'm sitting at a light or in heavy traffic and I take off the car will puff out blue smoke for a few minutes then clear up.
I decided to do a compression test last night and here are the results:
Cyl 1: 170
Cyl 2: 180
Cyl 3: 186
Cyl 4: 180

I believe this is good for a car of this age, but I'm wondering if it could be leaky valves causing this problem and wondering it I should just rebuild the head?

Thanks

Seerlah
06-04-2013, 04:32 AM
Cylinder 1 is the only inconsistent cylinder from the other ones. The numbers look really good, but not sure if that 16psi gap between cylinders 1 and 3 is something to be concerned about. All cylinders are still within spec. On my last engine (have not checked compression since rebuild) I had 160-170psi on all cylinders when it was running fine. This is when I like first picked up the car and ran it for years before the piston rings took a dump on me (after turbo install).

Ever consider your turbo being the culprit? Do a leak down test.

AudiTurbo
06-04-2013, 05:44 AM
Thank you for your response. I have had the k04 on there for less than 5000 miles and it was doing it before the install. What is the difference with leak down test and is there a DIY?

Thanks

M-Hood
06-04-2013, 08:52 AM
Thank you for your response. I have had the k04 on there for less than 5000 miles and it was doing it before the install. What is the difference with leak down test and is there a DIY?

Thanks

A leak down test shows you were the leak is in the cylinder and how much it is leaking.

woolveren
06-04-2013, 10:36 AM
I did the compression test on my car at 215k miles and these were the results

Dry Test:

Cyl 1- 205
Cyl 2- 200
Cyl 3- 210
Cyl 4- 200


And now it has got 255k miles.. I guess you should be okay with those differences in number..

redline380
06-04-2013, 10:49 AM
while low numbers could present a problem, the main reason to perform a compression test is to ensure all cylinders are within a specified range of each other. my haynes manual says they need to be within 30% of each other, which i think is a bit large. either way, the two cylinders furthest apart are #1 and #3, and they are within 10% of each other. that is perfectly acceptable. your engine is wearing fine. haynes also states that the lowest acceptable pressure is 101psi, so you have quite a ways to go.

the lower pressure in number hole is most likely due to something besides piston rings. something like a cam lobe more wore or a valve not sealing. since you have smoke as you said, it could make perfect sense you have a small leak somewhere in the number one hole. if you want, you can always rebuild your head, but it seems unnecessary with the amount of information given

AudiTurbo
06-04-2013, 10:59 AM
while low numbers could present a problem, the main reason to perform a compression test is to ensure all cylinders are within a specified range of each other. my haynes manual says they need to be within 30% of each other, which i think is a bit large. either way, the two cylinders furthest apart are #1 and #3, and they are within 10% of each other. that is perfectly acceptable. your engine is wearing fine. haynes also states that the lowest acceptable pressure is 101psi, so you have quite a ways to go.

the lower pressure in number hole is most likely due to something besides piston rings. something like a cam lobe more wore or a valve not sealing. since you have smoke as you said, it could make perfect sense you have a small leak somewhere in the number one hole. if you want, you can always rebuild your head, but it seems unnecessary with the amount of information given
Thank you for all the information. What other information do you need to give me more advice?

SN95Audi87
06-05-2013, 03:31 PM
Can a high quality oil can stop engines from losing compression or slow it down by 90-95%?

walky_talky20
06-05-2013, 05:08 PM
Well, ideally you are already using high quality oil, so...no. lol

I guess I would say it the other way: Using crappy oil and/or not changing it often enough will certainly accelerate compression loss.

SN95Audi87
06-05-2013, 05:24 PM
Well, ideally you are already using high quality oil, so...no. lol

I guess I would say it the other way: Using crappy oil and/or not changing it often enough will certainly accelerate compression loss.

Good point. Some engines just have amazing compression and I wonder if its from meticulous maintenance. I know that having an oil cooler and having stable oil temperatures most of the engine life will contribute to better compression then others. Routine flushes, and good oil intervals can keep the engine almost running forever imo, anyone agrees?

AudiTurbo
06-05-2013, 05:32 PM
For 157K I feel like I take great care of my car

walky_talky20
06-05-2013, 05:32 PM
Modern engine designs can certainly go tons of miles without a rebuild if kept maintained. We had a customer go 517,000 miles on a 1992 Camry 2.2L (5S-FE) engine. It got 4 timing belt jobs in it's lifetime, but NEVER a head gasket, piston ring, or rod bearing. The engine was never opened up, and never removed from the car. Still ran great when he was done with it, too.

SN95Audi87
06-05-2013, 05:37 PM
For 157K I feel like I take great care of my car

Me to man! The car runs hard, and I hope to get another 100k+ out of it with out a hitch.


Modern engine designs can certainly go tons of miles without a rebuild if kept maintained. We had a customer go 517,000 miles on a 1992 Camry 2.2L (5S-FE) engine. It got 4 timing belt jobs in it's lifetime, but NEVER a head gasket, piston ring, or rod bearing. The engine was never opened up, and never removed from the car. Still ran great when he was done with it, too.

This is what I am about. Really pushing the boundaries on how far a car should go. I think its worth it on Audi platforms since the mechanical structure of the car is built well even though it sometimes a pain to replace certain parts.

walky_talky20
06-05-2013, 05:42 PM
Yeah, the chassis is much better made (metal quality and rust protection) than that '92 Camry. MUCH better. And from what I've seen, the 1.8T engines can go a long way if you keep them well, and replace a turbo once in a while. So as long as you keep changing the various high-failure parts (we all can make that list), you should be able to take one to some extreme miles if you wish.

SN95Audi87
06-05-2013, 05:54 PM
Yeah, the chassis is much better made (metal quality and rust protection) than that '92 Camry. MUCH better. And from what I've seen, the 1.8T engines can go a long way if you keep them well, and replace a turbo once in a while. So as long as you keep changing the various high-failure parts (we all can make that list), you should be able to take one to some extreme miles if you wish.

Absolutely. This is my favorite reason. There are not many cars these days that have this type of quality, are they better produced now-a-days yes, but I can't account for the manufacture going that far to make the car last past 10 years through good/bad weather.

The high failure parts are on my radar and as I go into certain mileage (milestones) I see what I have to keep on top off. I have small fear about the tiptronic it has a hard shift at low speeds like city speeds. I just think the fluid needs to be replaced, but that can be a hit or miss. I think I am going to do it anyway, or I will never know.

walky_talky20
06-05-2013, 06:23 PM
I think you'll notice a lot of cars that hit 300k+ of any make are going to be manual transmissions. This is a reflection of more than just transmission longevity alone, though. Usually it takes a "car guy" to get a vehicle to go that far. "Car guy" usually wants his manual trans.

No fear on the Tip failure, though. You can always 5MT swap it when the time comes.

gmx
06-05-2013, 08:05 PM
I'm not sure if I'm way off base here, correct me if wrong. The main issue arises relieving pressure within the crankcase and head esp with the AEBs that don't seem to have enough venting. That pressure ends up sending oil past the rings. Does this continued activity somehow wear rings to not seal as well over time or is it simply going to cause less than ideal consumption and oil leakage/loss/burn?

M-Hood
06-06-2013, 07:07 AM
I'm not sure if I'm way off base here, correct me if wrong. The main issue arises relieving pressure within the crankcase and head esp with the AEBs that don't seem to have enough venting. That pressure ends up sending oil past the rings. Does this continued activity somehow wear rings to not seal as well over time or is it simply going to cause less than ideal consumption and oil leakage/loss/burn?

The increased crank pressure tends to effect how well the engine makes power and is usually the reason why people end up having oil leaking issues at the turbo since it increases the pressure in the oil system which is already high on its own.

AudiTurbo
06-06-2013, 08:11 AM
So, why am I blowing out smoke when I take off after sitting in traffic for a few minutes at a time?

Believer
06-06-2013, 08:21 AM
Could it be the valve stem seals going bad?

AudiTurbo
06-06-2013, 08:29 AM
That's what I have heard from some others. how hard of a job?