White "smoke"

[micbrody]

1981 Fi

I had car in garage for over a month without running it; and I had not disconnected battery. I started it to run and charge battery.

When car warmed up, I noticed "smoke" coming from bolt closest to firewall just near exhaust manifold. I believe it is a head bolt.
The "smoke" had no obvious odor; looked white: I think it is steam. When cool, I took oil cap of, the splattering of oil did NOT appear "milky".
I have never really rebuilt an engine, but here is my theory:
I have a head gasket "leak", but only path is the coolant to the head bolt. If this is correct, can I fix it by pulling head bolt and coat treads and shaft of bolt with hi temp thread sealer? Never did this stuff. If this would work, is there any danger of pulling bolt out?

[baltobernie]

It wouldn't hurt to try, but thread sealant is not strong enough to contain cylinder pressure. If you have a "path" in the head gasket from the cylinder to the bolt hole, the only solution is to replace the gasket. A leak from a coolant passage to the bolt hole might be sealable. You can diagnose with a compression test and an inspection of the spark plug. Head gasket-to-cylinder leak will result in a "steam cleaned" spark plug.

[micbrody]

I just read about product called Bar's Leak. Since engine is running fine, maybe I should try this? Anyone have experience withe this? And which formula would you recommend if you do recommend trying it?

[AriK]

Ive used Bar's leak on a disposable car and it does do the trick for a while. It also tends to make a mess of your coolant arteries and the excess sits in the bowels of the rad or heater core. I would not consider any vintage Spider as a disposable car.
I would go the sealer on the threads of the bolt route. Try to drain the coolant and get that area as dry as possible.

[klweimer]

Why don't you take a picture of the bolt in question? Might be useful for suggestions.
Kirk

[So Cal Mark]

bolts near the exhaust manifold are not head bolts, those are cam box bolts. That corner is a common spot to have oil leaks which is what your smoke sounds like, not steam

[micbrody]

Bolt in middle recessed behind distributor cap and heater hose with prestone cap






I never noticed it until car sat in cold garage. I guess it's possible that when engine started, there was condensation that dripped to the bolt??? or maybe a tiny leak in the heater hose connections?..... It just didn't look like at the time.


So what is that bolt?

[micbrody]

Mark,

Thanks for pointing that out. I did find an exploded schematic. I believe it is a bolt that goes through cam box to head gasket.

If it is oil, what should I do ?

[carl]

The bolt in the second picture (to the right of the body serial number) is not a head bolt, it is a cam box bolt. These bolts do not go through the head gasket, they merely bolt the cam boxes to the top of the head and the cam box has it's own gasket. Only oil is carried in the cam box, no coolant. Rub your finger under and around the coolant hose and see if the hose is leaking onto the bolt head. Also as noted one of the nuts that holds the exhaust manifold to the head may be leaking oil onto the exhaust manifold and burning the oil. Of the five studs that hold the exhaust manifold onto the head, the number 4 stud goes through the cam box and into an oil gallery. If the nut gets loose or the stud is loose oil will find it's way out to the end of the stud and down onto the manifold.

[micbrody]

Thanks for info. I'll check all those things. If it turns out to be coming from screw home , I'll just add some high temp sealant/ gasket to hole and re-bolt

[micbrody]

I'll apologize in advance for my lack of knowledge on the following:

I was going to remove the cambox to head bolt and put gasket/sealant in hole and retighten.
I have read a lot about tightening these bolts; and how I might have to adjust valve clearance.

I just don't understand why this bolt would cause valve "clearance" to change.......... I have never worked on engines; but in the diagrams, it just looks like it connects cam box to head......I just don't understand.

Also, some threads mention torquing the cambox down evenly to torque of 18 ft-lb. If I decide to remove bolt, should I loosen all the other bolts; and then sequentially tighten down gradually ntill all at torque spec?

Lastly, if I pull this bolt fully out, will oil leak up before I have a chance to add the liquid sealant/gasket?

[micbrody]

I guess I can conceptualize that cam is mounted on each end to cambox cover; so if gasket thicker or thinner, it would effect the clearances; just thought it would be "trivial"; unless new gasket way way thick

[klweimer]

If you are just pulling one bolt to seal the threads, I wouldn't worry too much about the gasket or re-torquing the other bolts. The gasket isn't going anywhere and is probably hard as a rock from age and heat. Just pull the bolt, put lots of sealant on the threads and torque it up. Not sure if the bolt hole will leak oil when you pull it, but I doubt it.
Kirk

[micbrody]

I backed out bolt; put some hi temp ultra copper gasket along upper shaft and under washer; tightened down. No "smoke".................however , as Carl suggested......I think I have a tiny coolant leak from one of the unions near Prestone refill T!!!!!

Such is life.......bottom line: I can fix that easily