368 LT5 Drinking oil

[Pete]

Originally Posted by Mitsumark

Pete-Car has 75k..Rebuild has 15k but it has lived on a road racing track and saw 150mph quite often as I have the cars racing circuit history.Ya know Im thinking.Wouldnt a valve problem show smoke on cold startup?Mine starts without smoke and starts to smoke a bit at idle once hot.I also noticed that it does not smoke on decell in gear at high rpm..Only under moderate pedal action and revving it in neutral..Im gonna try to shoot a vid on Thurs after work and I'll post up..I know a compression test is a must but Im driving myself crazy meanwhile..Worse case scenario.If the heads need to be yanked,am I gonna have to drag this thing to Chitown?Can anyone recommend a good LT5 wrench in NY/NJ?..I dont think VDs play with LT5 anymore and ECS only messes with LSX..I dont have the time or resources to attempt a repair like this..

Yes,your right about start up.
You mention it starts to smoke when she gets up to temp which I'm thinking oil thins out with hot temps.

Did this just start?
Basicly what was the last thing you did when this started.

Pete

[USAZR1]

Originally Posted by Kevin

I'm pretty sure Carmen and dennis didn't build your car.

Post edited by the Administrator.

[Kevin]

Post edited by the Forum Administrator.

[Dynomite]

Originally Posted by Mitsumark

If I blip the gas quickly 3-4 times back to back the smoke becomes heavier and heavier until I stop

As Jerry and Pete suggests...........Most likely its your Intake Valve Guide Seals or your valve guides. It will smoke during deceleration because the engine is pulling a higher vacuum (each blip) with the TB closed allowing minimal air going in to the cylinder while the cylinder vacuum is still able to pull your crankcase/oil through your intake valve guide seals. Seems to me I recall the 90' to 91' was the change to Valve Guide Seals (exhaust) with the Intake Valve Guide Seals available on both the 90' and 91'.

flyin ryan says 90' did not have exhaust valve guide seals but they can be installed

Description: 1990 Red/Red 21K - $ (AZ)
Very clean & original looking on the outside, cylinder heads & plenum (upper & lower) ported, new valve seals installed on the intakes & added to the exhausts (90's never came with exhaust valve seals), competition valve job, cams degree'd with ARP cam bolt's used, Accel injectors installed, 4.10 Mopar 'Viper' gears installed with a Ratech deluxe install kit & Dexron gear oil, Haibeck speedo calibration gears installed to compliment the gear change, C-4 beam plates, Doctor Don rebuilt & upgraded stereo, speakers & amps, Goodyear GS-D3 F-1 tires, Very strong but subtle running car, original paint with no touch up's, rims never seen a curb etc. Very well cared for no nonsense car, everything works, no issues.
Contact: Ryan Bell

Originally Posted by Pete

Did this just start?
Basicly what was the last thing you did when this started.

Pete

I was wondering the same thing ........when I asked if the 300 miles just before the last 300 miles was the same issue?

Another Idea.......to diagnose if the smoking is related in any way to the PCV System.
Disconnect your PCV system on Camshaft covers and Injector Housing (plug the associated vacuum ports on Air Horn and Plenum) and rev it up to see if it smokes. If the smoking stops you are getting oil through your PCV system into the plenum (Then we are back to rings gone bad or something peculiar with your PCV System).

If the compression is good you do not have a burnt valve or bad rings and then we are back to Intake Valve Guide Seals. I have no clue how bad Intake Valve Guides or Bad Rings would start smoking ALL OF A SUDDEN.

[USAZR1]

Originally Posted by Dynomite

As Pete suggests...........Most likely its your valve guide seals or your valve guides. It will smoke during deceleration because the engine is pulling vacuum with the TB closed allowing minimal air going in to the cylinder while the cylinder vacuum is still able to pull your crankcase/oil through your valve guide seals.

I agree with this,too.

[edram454]

Originally Posted by Dynomite

As Pete suggests...........Most likely its your Intake Valve Guide Seals or your valve guides. It will smoke during deceleration because the engine is pulling a higher vacuum (each blip) with the TB closed allowing minimal air going in to the cylinder while the cylinder vacuum is still able to pull your crankcase/oil through your intake valve guide seals. Seems to me I recall the 90' to 91' was the change to Exhaust Valve Guide Seals.

flyin ryan says 90' did not have exhaust valve guide seals but they can be installed This being a 91' with 91' heads makes this information not relevant but just informative for others viewing.


I was wondering the same thing ........when I asked if the 300 miles just before the last 300 miles was the same issue?

my two cents. yes Lee the 1990 did not have exhaust valve seals. the difference is the 1990 will smoke a little at the initial start up.. once you drive around and gets warm... no more smoke.. at all. His is smoking at deceleration, idling.. I would think he would need some type of valve work on his heads. Hope I am wrong.

[XfireZ51]

Originally Posted by edram454

my two cents. yes Lee the 1990 did not have exhaust valve seals. the difference is the 1990 will smoke a little at the initial start up.. once you drive around and gets warm... no more smoke.. at all. His is smoking at deceleration, idling.. I would think he would need some type of valve work on his heads. Hope I am wrong.

Smoke at idle and decel means it's sucking at the highest vacuum conditions.

[USAZR1]

Post edited by the Forum Administrator.

[A26B]

Originally Posted by Dynomite

.........
When you do the compression check....squirt some oil in in spark plug hole after initial compression check and recheck....I think that is what Jerry is suggesting to distinquish between Valves and Rings.

You would be correct in your thinking.

[alnukem]

After the compression check, wouldn't the next check be a vacuum gauge?

Steady idle Fast fluctuation between 14 to 19 points Worn intake valve stem guides. Excessive pointer vibration at all speeds indicates a leaky head gasket.