Hitting max boost, but car goes no where..

[PieEyedPiper]

It only happens when its hot, or after I've been boosting the whole way across town. I'll be around 2k rpm, and I'll wanna giver some gas so I do. I hit max boost ~14lbs. and the car just doesnt go anywere. It's fairly intermittant.

I don't think its a boost leak cause I can pressurize my intake to about 18-22psi, which is defintiely above my current boost levels.
I also have low compression on 2 cylanders. going from passenger side to driverside.
180 181 149 151

Hope thats enough info for ya.

 

[TuRBoTaLooN]

You said this only happens when its hot or you have been boosting a lot, which leads me to believe that your stock smic (assuming that is what you have) is heat soaked as sh*t. I get the same problem in my 95 TSi. Your best bet would be to upgrade to a supra smic for like $100-$150 and it mounts in the same place with very minor modification. It cools about twice as much as the stocker.

Just in case you don't know what heat soaked is, it means that the intercooler is unable to effectively cool the air coming into the engine anymore which means the air is wamer and less dense which means your car puts out less power. You could boost 20psi with warm air and get more power out of like 5psi of COLD air. Cold air is more dense and creates more power upon detonation.

Hope this helped, good luck!

 

[PieEyedPiper]

I'd thought about my little smic getting heatsoaked when this last happened to me (last night), but I dismissed it since my logger indicated intake temps of around 66F.
Maybe I can setup a temp probe attached to my smic and find out if I get this issue only when the ic is at its hottest..

*runs to radio shak*

Thanks, more input appreciated.

 

[super97gst]

run a log while its doing this and see if its pulling timing. i have been having this problem for a while now and ended up a guy on here found out for me that it was phantom knock. 3rd gen lifters fixed this problem on my gst. check my thread on the problem diagnosis forum. i just posted that thread like a couple weeks ago i think. it'll prolly tell u exactly what u need to know. hope this helps man.

 

[VBGSX]

I'd thought about my little smic getting heatsoaked when this last happened to me (last night), but I mismissed it since my logger indicated intake temps of around 66F.

Don't dismiss it because the logger says the intake temp is around 66F.
Intake temps are measured pre-turbo at your mass air sensor. It won't tell you anything about post turbo/post IC temps. Since you say it happens when the engine is hot or after you've been boosting across town, you could be heat soaking the IC, etc.
This could very much be real knock, yanking your timing.

run a log while its doing this and see if its pulling timing. i have been having this problem for a while now and ended up a guy on here found out for me that it was phantom knock. 3rd gen lifters fixed this problem on my gst. check my thread on the problem diagnosis forum. i just posted that thread like a couple weeks ago i think. it'll prolly tell u exactly what u need to know. hope this helps man.

Definitely.
If your logger is showing your timing being pulled......knock(real or phantom). Like I said above. Since you say it mostly does it after boosting across town or when the cars hot, it sounds more like real knock, possibly because you've heat soaked your little IC and everything else.
It would also be interesting to see your engine temps(per logger) when this happens
Good luck
super97gst. glad you got your car fixed

 

[PieEyedPiper]

Great thought on this guys, much appreciated. I THINK my engine temps (coolant temps) were around 206F at the time..within normal range no?

I'll perpetually have my logger logging rather than displaying, until I happen upon this problem again and we'll see whats what then



Thanks!

 

[oldman]

Great thought on this guys, much appreciated. I THINK my engine temps (coolant temps) were around 206F at the time..within normal range no?

I'll perpetually have my logger logging rather than displaying, until I happen upon this problem again and we'll see whats what then



Thanks!

Didn't we determine you have ring problems on two cylinders in the other thread?

 

[PieEyedPiper]

well yeah..
its one problem after another..

you think my periodic (happened AGAIN tonight) gutlessness under boost is related?

eug i need someone to donate me a nice new engine..
and now my rear end is ticking..

but at least i got hammered tonight and hit on the chick from american idol. (not even joking).

 

[kristmen]

... Dude if you are having ring problems of corse that would affect your car and give it that lack of balls feeling.

Thats sorta like saying well I know my head gaskets blown and I've got a 90 compression on 2 cyl's but do you think that could have anything to do with why I got coolent in my oil? For a lack of better thing to compare to

 

[oldman]

you think my periodic (happened AGAIN tonight) gutlessness under boost is related?

If memory serves me right, the wet test was 220+ for the two lower cylinders so yes, they can be related. I was also helping someone else with a intermittent stuttering problem and it turned out to be FIAV leaking after car warms up, you might want to look into that as well.

http://www.vallotton.com/fiavblockoff.asp

 

[PieEyedPiper]

If I get the balls to dismantle my tb and figure out what to do with the coolant lines I"ll deifnitely try it.

But yeah, I realize that if im having compression issues I can expect to see a few symptoms, this problem of mine doesnt happen all the time though so I figured I'd at least ask around before chalking up everything that goes wrong to two low cylinders.

Thx!

 

[super97gst]

well its not a total loss then

 

[PieEyedPiper]

haha you bet!

so today i changed my oil. I was gonna try something heavier than 10w 30 cause of my lame compression, but instead I decided to dump half a can of seafoam between my 2 low cylinders, wait 30 min, put my plugs back in and start up the car. I drove around for about 10 min getting rid of all the white smoke..which eventually started to come out blue.. (??) I rode her hard until all the smoke was gone. I came home and drained the oil. I replaced it with 3.5 parts valvoline 10w 30 and 1 part "restore" a oil additive "garaunteed to restore compression in 500miles or your monye back".

So while I'd love for it to be a solution, at the very least it should be healthy for my car.

 

[PieEyedPiper]

I swear I'm loosing my head. The car drove like shit today, as predicted..

BUT since I changed my oil and used that restore stuff, i figure why wait 500, lets do a compresssion test now and THEn after 500 miles to see if i can gain a few psi in that time.

So I tested. 3 times each cylinder.

185, 180, 180, 180.

no joke. perfect compression across the board.
I have no idea why, but I tripple checked and got the same result everytime.

I then moved onto yet another leak test since the car was still running bad all day. I only managed to build 5psi this time..eug. I spent 40min trying to find th leak but no such luck.
My BOV was leaking at 1psi. I plugged it with a D battery and I could hold 5spi. My breather filter leaked like a bi***..but oldman advised me not to block it, so I just left it.

I'll ahve to check again tomorrow for the leak.

 

[oldman]

So I tested. 3 times each cylinder.

How many times did you repeat the test when you got bad comprssion last week? Was car fully warmed, full throttle applied and good charge on the battery during the initial test? Did you do a wet test this time?

I then moved onto yet another leak test since the car was still running bad all day. I only managed to build 5psi this time..eug. I spent 40min trying to find th leak but no such luck. My BOV was leaking at 1psi. I plugged it with a D battery and I could hold 5spi. My breather filter leaked like a bi***..but oldman advised me not to block it, so I just left it.

Definitely do not plug it up, this is very important. In fact, I want you to open your oil cap from now on when pressure testing, you want air to escape immediately so you don't build up crankcase pressure.

That's re-group and go back to the basics.

1. Is the exhaust smoking under any circumstances?

2. I think you replace the pcv with an oem one, right?

3. Last time when you pressure test, you were able to build only 11psi at turbo inlet but 18psi at TB elbow, is that right? Give us a review.

4. If I remember correctly, you disabled the actuator completely and did a all out boost test run but the problem still persisted, right? Again review please.

Please be detail on your responses.

 

[PieEyedPiper]

Thank you for sticking it out with me. I'm beyond greatful.

During my initial testing, I had just taken the car for a drive (20min), and after discovering the low compression on cylinder 3 and 4 (the two closest to the driver side) I of course would not accept no for an answer and tried and tried again. I must have tested both the low cylinders 4 or 5 times each. The first time I cranked it for 4 revolutions, and got ~120psi. I then tried again, but I let her crank for around 8 revolutions, and I leveled out around 150psi for the next 4 or 5 times I tested that cylinder. I had an identical experience with cylinder 4.

For all tests, I had the gas to the floor with all my might and the clutch in. The engine was warm, It had only been shut off long enough to print out the intructions on which fuse to pull and what plug to pull to stop me from getting any spark.

1. Under no circumstances has my exhaust ever smoked unless I had been performing a wet test or been using seafoam.

2. I replaced my pcv valve with a non-OEM Napa valve before I learned they were junk. After considering that today during my most recent boost leak test, I unplugged the hose attached to the pcv and could not detect any leaking from that port.

3. During my last (prior to today's adventures) boost leak test I was only able to build ~11psi at the turbo and ~18psi at the TB. This is while plugging up my BOV. I discovered a boost leak at a vacuum hose directly beneath my battery. I fixed it.
Today I performed another boost leak test and discovered I could build 0 boost whatsoever. I was spraying everything I could with a soapy solution to try to uncover my problem. I eventually replugged my BOV which was clearly leaking pressure at 0psi. I was then able to build 5psi. As I stated above, my breather port leaked a lot, and my pcv valve remained a non-integral part of my testing (as far as I could tell). If I covered my breather port with my thumb (to gauge how much air was really coming out from there) I would then see tiny bubbles appear at the front left corner of my valve cover. They were only present when I plugged the breather port with my thumb (which I will not do, and I will leave my oil cap off for all future tests). After shutting off my cigarette lighter compressor, I could hear a drip drip drip sound coming from underneath my valve cover (This is me being detailed). I tightened everything I possibly could and checked all my IC pipes for a good snug fit, included tightening them all up. I could still build no more pressure. I could not hear a leak from anywhere, nor see one, despite my vigorous spraying of soapy water. I was running late for work, so I slapped the intake back on and took off. I could boost to 13lbs which held tight the entire way to work. My car still felt sluggish and not overly peppy (while still being 100% better than the issue I originally started this thread for. I did not have this issue today). End result of my testing was 5psi.

4. I don't think so cause I don't really know what is entailed in that.

I suppose its possible that on cylinders 3 and 4 I had gummed up sticky rings, and the seafoam I drowned them in (half a can between two cylinders is a fair bit right?) loosened them up over the 30min I let them sit. I highly doubt the "restore" has had any impact on my compression test, but thats purely conjecture.

I will test my compression again tomorrow to ensure I didn't somehow get freak results. I will also do a wet test, as I did not perform a wet test today. Though would I not get sky high compression on a wet test even if the rings were good? I mean if they're making a perfect seal, and I threw in some oil..common sense tells me they will seal even more with the added oil. But maybe I'm not grasping a concept here. Regardless, I will perform a dry and wet test tomorrow.

EDIT: I forgot to mention I got 2 CEL codes when i went to go to work. Intake temp sensor, and intake manifold pressure. I cleared them both. I presume they're harmless and I recived them cause I was messing around under the hood only 10min earl;ier with my compression and leak testing.

 

[oldman]

I'll have to give this one some more thoughts as there're a lot to obsorb, hopefully I will be able to respone during lunch time tomorrow. I suggest that until you get this figured out, ease off the throttle, no boost what's so ever. Everytime you boost you're pressurizing the crankcase which can do a lot of damage. Make sure you plug back the pcv to intake manifold to ensure the crankcase is vented properly.

 

[oldman]

Let's go back to the basics again without thinking about prior test results for now.

1. compression test.

2. pressure test at the turbo and TB.

Repeat these test again to ensure proper procedure and confirmed which of the prior test results are accurate.

VBGSX, and anybody reading this, any input? Feel free to jump in with ideas, I think I'm too involved in this one, I may be over looking something.

 

[VBGSX]

I'm here
Wow that's a lot of info to take in. I've got some ideas. I'll be back in a sec.
I was trying to sit this one out... I think you had covered most everything and I didn't want to requote what you already said.
Let me reread this again and gather my thoughts
BRB

 

[PieEyedPiper]

And I'll re-test everything as soon as I get off work, and give us all some more accurate and fresh results.

 

[oldman]

And I'll re-test everything as soon as I get off work, and give us all some more accurate and fresh results.

If all possible, borrow a different compression tester and have the battery jumped during the test to ensure equal crank on all four.

 

[VBGSX]

Wow, where to start..

Correct me if I'm wrong but it sounds like the most recent boost leak test you conducted was from the turbo back.
If so:
I believe it's already been determined that you're probably leaking pressure through the turbo seal. If this is the case, this pressure will make it's way down the oil return hose, pressurizing the crankcase.
The reason you DO NOT plug the PCV or breather port is because that pressure has to escape. If it doesn't leave through the beather or PCV line it will then take the next easiest route.....your gaskets. That will/could create a very bad day for you!

Now, ways you can pressurize the crankcase(I may miss one so bare with me):
1. Turbo seals
2. PCV valve
3. Compression rings
4. Valve guide seals
5. Head gasket

Causes for boost leak test bad results(I will probably miss 1 or more plz bare with me).
1. Leaks at the BOV(vacuum line, BOV port, BOV gasket)
2. couplers
3. Turbo seals
4. PCV valve
5. Compression rings
6. EGR valve(might want to look at this carefully**)
7. TB(seals, vacuum lines, BISS screw, gaskets)
8. vacuum lines(all of them...)
9. Intake mani gasket(very rare if the stock mani has never been removed)
10. Injector seals
11. Valvle guide seals
12. Engine(crank at the wong position, valves open)...good possibility
13. This list could go on and on and on and on.

So lets take what we can out of the equation:
1. Turbo
2. Disconect the PCV hose from the intake mani and cap it off at the maini.
3. IC pipes
4. IC
Bare with me on the last two. This will make sence in the end(below #5)

Now lets start from scratch(as oldman stated)
1. Compression test
2. Get your soapy water ready(spray bottle) and spray everything in the above.
3. Disconect the PCV vacuum hose from the mani and cap the mani first.
4. Boost leak test at the turbo: Write down your results. Check for air at the breather.
5. Do another Boost test at the TB. Write down your results and check for air at the breather.

If you're still getting a ton of air out the breather when you do the test at the TB:
1. Compression rings
2. Valve guide seals
3. Head gasket

If you're still leaking air fast but not much going out the breather(testing at TB):
1. Engine in the improper position
2. EGR valve
3. TB(gasket, seals)
4. Injector seals...usually a big problem
5. Vacuum hoses

As you can see, we're slowly narrowing things down.

I would bet that if you did the compression test correctly all the times, the seafoam was the helping factor to loosen up a possibly problematic compression ring(carbon that made it's way down). Until you mentioned that your results went back to normal I was starting to think you possibly had the makings of a bad head gasket. Not sure now. That's why we need the retest from scratch.
As of right now, I think you probably have several problems going on at once.
We'll nip them one at a time.

I'm glad you at least have a cigarette pump but the one problem with them is that they make a lot of noise. If they were quiet, you might be able to hear is the pressure is escaping out the exhaust.
1. Improper engine pos.
2. EGR wide open
3. Valves in general

As I stated a couple times above. I'm sure I forgot a couple things so please bare with me and feel free to add what I forgot.

Sorry it's so long but I hope it helps

 

[oldman]

^^^^ Are you trying to write a book?
I think I can go take a nap now, let me know what you guys find.

 

[VBGSX]

See what happens when you get me started

Even worse is I have more in me

To the thread starter,
make sure your compression testing is consistant for all cylinders
not 4 cranks for this one and 5 for that one.
Everybody is different but I do at least 7 revolutions....that's just me though
http://www.dsmgrrrl.com/FAQs/compression.htm

 

[PieEyedPiper]

Ok finally it stopped raining and I went about my testing, all from scratch.

Compression Test Results:
185, 181, 181, 178

This time I started at the driver side and ended at the passenger side to see if my results changed due to battery charge. I recieved identical results to my previous testing. cyl 1 one still being the strongest and 4 being the weakest of the bunch. I thankfully have near perfect compression, or as good as it gets more or less.
I also held the key for 8 full revolutions per cylinder and the engine was tested maybe 5min after a 15min burn across town to charge the battery and bring the engine up to operating temperature.

I did not bother with a wet test becuase, well, I recived no indication I needed to.
I think we can rule out rings.

Boost Leak Test Results:
1a. I pressurized the intake tract from the turbo. I recieved 4psi.
1b. I plugged my bov dump tube with a D size battery. I recieved 9psi.

2. I pressurized my intake tract from the Lower IC port. I recieved ~10psi.
3. I pressurized my TB. I recieved ~10psi.

During my testing, I left my breather port unblocked, but I didnt really get much air out of it. This is because I left my oil cap off as suggested.
During the first 1/3 of my leak testing, I could hear whoosing from my oil cap, and hear bubbling of oil (drips it sounded like.. but i think thats bubbling).
For the following 2/3 of my testing there was no bubbling/dripping sounds, but lots of air continued to exit from my oil cap.
I also found that if I disconnected my tube going from the PCV to the Mani. I built ZERO Pressure. If I reconnected the line I built pressure.
At no time could I detect air leaking from my exhaust.
I also re-installed my BCS restrictor. I noticed no difference in max boost attainable. (does what MIGHT be 0.5psi decrease count?)

I took the car for a spin and she purred nice and smooth. I did get two CEL's. intake temp sensor and intake manifold pressure again. I cleared them and carried on my way.
I had no problems driving, no stuttering or lame performance that I could percieve. But I THINK I noticed a difference in how the car boosts with the BSC restrictor re-installed, could be a placebo, but I think the car runs more smoothly under boost with it in.

Anyways, lets get back to the Facts and away from the "I thinks".
I logged a 3rd gear run for you guys to examine as well.