Flaming Heat exchanger, please help!!!

[AlienTekniX]

I know this isn't the first oil burning heat exchanger, but I have a weird issue that I hope someone who has looked at the motor from a builder's point of view may know what to look for.

I have a leak that drops on the heat exchanger on the left side directly in front of the exhaust outlet from the cylinder head closest to driver position . I have just put on turbo valve covers + weltmeister gaskets. I do NOT believe it is coming from the lower valve cover any longer. I have on two occasions cleaned the area around the valve covers that collect oil and driven the car on short trips (10 min or less) and it stays dry with a oil drop spot that centers exactly in front of the exhaust outlet right where the exchanger slopes down. The oil collects through the slits where the pipes exit the exchanger and when I drive it during the day it starts a small oil fire inside the exchanger pan, releasing a ton of nasty smoke all at once when it lights up. (yes I have been pulled over by a sheriff for a burning car!) I also don't believe it is the oil return tube, it appears dry and too far away, so does the lower valve cover for that matter. Looking at the engine from the bottom I don't see anything else that easily explains the leak.

It has been suggested to me that the top valve cover maybe the culprit and it does seem to be the only thing that could line up so centrally to the exhaust outlet if it dropped from the top and front of motor BUT the upper cover seems to be dry at least from the above the line of the engine tub. I cannot see the front of the motor. Maybe it can leak and not be seen from above the tub? I'm still too new to the motor, can you guys give me some insight???

[911pcars]

Gravity has a way of masking the true source of our oil leaks.

The items above the valve cover that can leak (driver side) include:

a. Camshaft lube hose/fitting
b. Upper valve cover (although you checked this as a non-source)
c. Rocker arm shaft
d. Joint between cam housing and cylinder head
e. Oil drain tube (x2)

Start with a thoroughly clean and dry underside. This temporary state of being can be achieved by visiting a local self-serve car wash. Jack up the rear and clean the underside, then....

For (a), shine light at area and look for wetness.
For (b), you checked and verified no leak
For (c), remove lower valve cover and inspect "dry" areas on either side of rocker arm. If they're wet with oil, oil is leaking past the shafts.
For (d), lay on back with engine running and observe. Some techs pour a flourescent liquid into the oil that can be observed with a black light. No gasket here, just sealant.
For (e), observe while running.

Hope this helps,
Sherwood

[AlienTekniX]

Just to try to help explain the position of where the leak ends... On the old school exchangers there are three pipes and then the large tube that attaches to the hose that leads to the passenger compartment for heat, the drip ends up on the large tube to the right of the three exhaust pipes. Right above the exchanger pan, where the exchanger is the largest and begins to slope to the rear (exactly the place if you want oil to collect). It is the most forward cylinder closest to the driver on the left one inch in front the exhaust outlet of that cylinder, exactly center with it.

If it helps and it may, it only seems to happen when running hard(freeway speeds) and or hot days. It is much less pronounced at night or short distances. Maybe oil is thinner cause of temperature?

Sherwood thanks man I will try to figure out if it is (D) and find out the location of the joint between the cam housing and head, anything I can use as an identifier there???

[AlienTekniX]

If it helps anyone...
I covered the heat exchanger with tin foil so oil does not build up in the exchanger. Voila! no fires, does it fix the problem... nope, but it may keep you going until you can fix it. For now until I locate the actual issue I can drive without being a fire hazard.

[Hoffmanmotors]

I had this very problem. The culprit on my car was my oil thermostat o ring was shot, oozed oil and dripped on both exchangers. I still have to take off my exchangers and clean out the oil that collected inside. Yes it sucks, all the dang smoke!