White smoke question

[killab443]

First let me start by saying I just installed an engine into my car 1g fwd turbo. Its a rebuilt motor with some miles on it. Compressions is 150 across.Im getting some white smoke out of my exhaust. My turbo is 125k old and I was thinking maybe it has bad coolant seals. Is it possible that this is causing the white smoke? Regardless it still boosts does that sound right?

 

[luv2rallye]

Compressions is 150 across.Im getting some white smoke out of my exhaust. My turbo is 125k old and I was thinking maybe it has bad coolant seals. Is it possible that this is causing the white smoke?

Yep...you nailed it.

 

[ddavisaf]

Your turbo does not have coolant seals. Yes, there is coolant that runs through your turbo, but there are no seals.

Are your sure the smoke isn't grey? Indicating you're running rich....
Smell it, remember to "waft" it to you, don't stick your nose in the exhaust. Does it smell like burnt maple syrup? That's coolant.
Any CEL's?
And by smoke, what do you mean exactly? At WOT only, at idle only, after boosting only, what?

 

[killab443]

It only does it some times at idle and when I rev it to around 4k. Also when I get out of the car after driving on it, pop the hood and the turbo is smoking. Now it's not smoking from any particular spot. I check around and notice its coming from the o2, and were the runners meet the head. This could also be smoke that is rising. Any ideas? O yea and another thing, after bringing the car to normal temps (5min of driving) when I take my foot off the gas it dies and fights to stay running. From a cold start it idles fine. When the car is started there is no CEL

 

[ddavisaf]

Start by pulling the LICP and checking for oil, post back what ya find.

 

[killab443]

I pulled the licp after a nice ride in the car. I found that there was minimal oil in it. Not really to slick in it. I pulled only one plug to find that the top of the piston was shinny. and the plug was pretty black. Any ideas? im going to check the restof the plugs in a little bit

 

[ddavisaf]

Sounds like your compression test was wrong. Only time I personally have seen shiny piston heads are either forged pistons, or a blown headgasket.... pull the rest and check 'em out.

 

[killab443]

Just pulled all and compression tested 150-155-160-165 #4 had a oil on the top of the plug because of a bad vc gasket resulting in better compression.

 

[ddavisaf]

when I take my foot off the gas it dies and fights to stay running. From a cold start it idles fine. When the car is started there is no CEL

My car stumbles/misses when I let off the throttle! Is there a fix?

The general consensus is that this is caused by the BOV, which can stick or plug. This appears to be especially true of the 2G BOV, although some 1G owners have had this problem as well.

Alexander Kowalski's Jan 27, 1999 fix to his off-throttle stumble went like this (edited for presentation):

"I took the BOV off a today for a closer look. I found some RTV plugging up a 3 mm diameter hole at the base of the BOV. This hole appears to be part of a passage in the BOV casting that travels straight up to the top. I am assuming it is some sort of return relief passage.

Not only did clearing the RTV solve my off throttle stumble, my BOV no longer sounds like a loud bird shriek between shifts. Its more like the soft 'phfft' sound I have associated with my two previous BOVs. Darn, other than scaring the heck out of my wife I really liked that sound."

Cleaning the BOV, replacing it or upgrading to a 1G unit should solve the problem. Owners of adjustable BOVs report that setting the BOV too tightly will cause this same problem, so a quick adjustment may be in order.

Owners who are having the problem with the engine RPM dropping abnormally low after letting off the throttle may be having problems with the speed sensor or idle switch on their cars. If one of these is malfunctioning the ECU may not realize the throttle is at idle until the engine RPM drops below the normal idle speed.

 

[killab443]

That doesnt explain why it works from a cold start. I think the plugs might be getting saturated with oil after the car runs for a little.

 

[ddavisaf]

Well, when you ran your compression test, did you do it when the car was at operational temperatures?
What you're refering to is blow by, which is causing by failing piston oil rings.... meaning lower compression

 

[killab443]

ive heard you can have bad oil control rings and still have good compression so I dont think that is true

 

[ddavisaf]

No, bad rings means bad compression. Think about it. They seals the oil underneath of the piston, so if they're bad and allowing oil past, your air from the compression test would skip right by the rings lowering your compression.

I forgot to ask, what fluid are you losing? Oil or coolant?

 

[killab443]

I don't even know thats why I posted

 

[ddavisaf]

You don't know if you're losing any oil or coolant?