engine and drivetrain Help! Confusing smoke issue: 1974 2002Tii

[achman]

Hello all,

New to the forum and have a question I hope someone may be able to shine some light on.

FYI I have spent the past two weeks researching the issue on this forum and other places, and cannot come up with an answer. I am not just walking in and expecting an easy fix without doing some of the pre-work!

This is a car I am seriously looking at purchasing.

1974 Tii 278VIN, sunroof, 110K original, original CA blue plate, Malaga car, repainted once, paint 7-7.5 out of 10

New distributor cap, rotor, points

New fuel & air filters

New motor oil & coolant

New spark plugs & wires

Mileage: 110000 original. Engine and fuel pump not rebuilt. K-injection intact and working.

Compression test: cylinder 1 was 155, the others were 150.

leak down test: 28% for #1, 12% for 2 and 3, and 18% for 4.

I drove the car for at least 45 min, and it drove very nice.

Engine pulls well.

At first it idled lumpy and too high, then seller realized secondary breather hose not attached. Owner put it on and it smoothed out.

I drove it on windy roads, stop and go traffic, and easily accelerated to 75mph on freeway, drove for 10 minutes at this speed. Good power, easy to maintain speed. No overheating.

THE ISSUE:

The only issue that concerns me is a smoking issue that both the owner and I can't figure out.

--Car smokes-- white smoke (not blue or black)--mostly only at idle.

--Car does not smoke while accelerating, or on overrun (the typical blue smoke valve issue)

--Car makes good power and good compression and leak down test is not horrible.

--No coolant in oil.

--I smelled the smoke, but it did not smell sweet or coolant-y.

Can anyone give me any ideas as to what the smoke may be?

[FB73tii]

Brake fluid level stable?

--Fred

[Paul7002]

How Much "smoke" ? Billowing clouds or just enough to notice. Could be water vapor - a natural by-product of burning gas.

[Mikesmalaga72]

Hmm New York...What was the ambient temperature? It could merely be just steam due to outside air being cooler than the exhaust temperature. Sounds like a cool car! I would take it back into a properly vented warmer garage and see if it changes.

[c.d.iesel]

all the prelim readings indeed excellent - good health

the white smoking at idle can be coolent because at idle

the exhaust cools down and the tiny amount of coolent

leaking into the combustion

chambers does not burn off completly

under load and higher rpms, combustion and exhaust temp

raises and it's able to cook off the small amount of coolent-

so no smoking

removing the spark plugs will tell you almost all you need to see

there is a chemical test for radiator coolent - to detect the

presence of combustion gases in the coolent. The tester chemical

is contained in a clear tube attached to the top of the radiator.

The chemical will change color if contaminated

the condition of the motor by compression and cylinder leak

test says no problems - but under load and actual running conditions

it may be just starting to leak - and when the car is subject to daily driving and long distance - what tiny head crack, headgasket leakage will open up to full blown failure.

if the head has never been off this motor - it's just waiting

for the next owner to fail - after it's driven like a tii should

a through repair history of this car would help you make a decision

as to it's past care and maintanence

[achman]

Thanks for all the great responses!

@Fred

Brake fluid level stable?

Yes, checked for brake fluid leakage, and that is not the problem.

@Paul7002

How Much "smoke" ? Billowing clouds or just enough to notice. Could be water vapor - a natural by-product of burning gas.

@Mikesmalaga72

Hmm New York...What was the ambient temperature? It could merely be just steam due to outside air being cooler than the exhaust temperature. Sounds like a cool car! I would take it back into a properly vented warmer garage and see if it changes.

I would say a medium amount. Here is a quick video of the smoke: This was after a 45 minute drive, followed by 20 minutes of sitting in 40 degree cold air.

http://www.youtube.com/watch?v=LWjmPuWIWIE&feature=youtu.be

@c.d.iese

if the head has never been off this motor - it's just waiting

for the next owner to fail - after it's driven like a tii should.

A through repair history of this car would help you make a decision

as to it's past care and maintanence

Head has never been off as far as I know, no repair history is known.

Front windshield seal is original and does leak, is there any way water could be getting into exhaust that way? There is no rust there though...

Also owner used BG-44K in the fuel system and possibly oil to clean everything out. He thinks it might be this, as the car didn't smoke previously. I should have mentioned that.

[c.d.iesel]

that's coolent ! the smoke is lingering and excessive to be

just 'clean' steam

http://www.youtube.com/watch?v=LWjmPuWIWIE&feature=youtu.be

[achman]

that's coolent ! the smoke is lingering and excessive to be

just 'clean' steam

http://www.youtube.com/watch?v=LWjmPuWIWIE&feature=youtu.be

So best case, head gasket leak, worst case, cracked head and full rebuild/replacement?

If there is a head gasket leak or crack, then why do the compression and leak down #'s look good?

[c.d.iesel]

.....if there is a head gasket leak or crack,

then why do the compression and leak down #'s look good?"

because the crack in the head hasn't opened up or the head

gasket hasn't split open - looks to be just a tiny leakage at this point-

but so slight that the cylinder leak test does'nt reveal it yet.

Drive it for a 200 miles 'hard' trip and it'll probably lay down

a smoke screen that'll look like a WWII sea battle!

like i said - if you remove the spark plugs - you'll see

signs of 'stuff' entering the combustion chambers

and depositing on the plugs

[achman]

.....if there is a head gasket leak or crack,

then why do the compression and leak down #'s look good?"

because the crack in the head hasn't opened up or the head

gasket hasn't split open - looks to be just a tiny leakage at this point-

but so slight that the cylinder leak test does'nt reveal it yet.

Drive it for a 200 miles 'hard' trip and it'll probably lay down

a smoke screen that'll look like a WWII sea battle!

like i said - if you remove the spark plugs - you'll see

signs of 'stuff' entering the combustion chambers

and depositing on the plugs

thanks for the opinions...

As for a head gasket replacement, I am assuming if that is the issue you should go ahead and have the head redone in addition. Correct? I would assume the valve guides are original, but I do not know.

If it is a crack, that could only be found out if it is removed and tested for cracks correct?

Any guesses as to what a head rebuild would be?

[Mike Self]

or more cylinders--had this happened to my '69:

There are water passages in the head over each exhaust port. When the engine is shut down, localized coolant boiling takes place in those passages due to residual heat from those exhaust ports and the iron exhaust manifold Over some years the boiling gradually eroded the aluminum in the coolant passage--which is only about 6mm from the edge of the combustion chamber--until a tiny hole opened up into the combustion chamber.

My car was losing coolant--no more than a pint or so in 800 miles--but it was losing it--compression was fine, engine made plenty of power, sniffer didn't reveal coolant in oil or oil in coolant. Finally found the problem on the umteenth compression test when I pulled #1 plug and it was wet with coolant. Pulled head, gasket wasn't even blown.

Local machine shop used the head gasket as a template, welded up the head (the other 3 passages were eroded too) and planed the head. Reinstalled it and that solved the problem. That was around 1987 or so, and it's been running just fine ever since...

mike

[achman]

Thanks for the tip. I will check the plug for coolant if I get a chance.

BTW, I am in NYC but originally from Beavercreek, off of Lantz Rd.

Small world!

[Chris_B]

I agree with CD that this does look like coolant in the exhaust and that coolant leaking into a cylinder will effect the plug, but usually will scrub the plug very clean- not expressed as deposits on the plug.

[Mike Self]

tend to steam clean the spark plug(s) so that the affected plug(s) will tend to be cleaner than the others.

I only live a couple of miles from Lanz Rd in Beavercreek--didja have your 02 when you lived here?

mike

[sdmurphy]

Cracked head. Looks just like mine did. Crack between the intake and exhaust valve in #3 cylinder. Sourced new head and did a complete rebuild.