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Oil Leak Under Cylinder Head

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davidk

davidk

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After 9 months of converting to TBI fuel injection (which works great by the way), I'm enjoying driving my 1974 TR-6. I didn't drive it much after I bought it nine months ago because it was running very rich, and had a leaky fuel tank, I only drove it a few miles before starting to work on the fuel injection. Now, after about 200 miles, I'm noticing a pretty significant oil leak between the cylinder head and the block on the drivers side of the engine. My first thought was head gasket, but I'm wondering if anyone else has had this problem, and if there could be another source. I really don't want to take it off the road, but I also don't want to cause any damage by driving it. From the diagrams I've seen of the Triumph head, it looks like the water galley's are on this side of the engine, so it looks like the oil would have to go around them if it is coming thru the head gasket. I haven't noticed any oil in the water, or water in the oil, just oil between the head and the block. There seems to be more in the back than in the front. I don't think it would matter, but this is a 2 liter engine from a 69 or 70 GT-6 Plus. Has anyone experienced this type of leak? Thanks for your help. David K.
 
I just looked at my block and cylinder head, which happen to be conveniently located in my basement and the pushrod passages are on the driver side not the water jacket. I think you will have no other option than to take the head off and replace the gasket. Sorry! /bcforum/images/%%GRAEMLIN_URL%%/frown.gif
 
I would re-torque the head before replacing the gasket. A lot of the 6 cylinder BMW’s were prone to leak oil around the cylinder head but I don’t recognize that problem to be common to the TR6. I presume you are sure it is not the rocker cover leaking, the PCV system leaking, and no leaks from the (owner installed, if it is there at all) aux oil line for the rockers; right? BTW, not that it should matter, but what oil are you using?
 
I agree about trying a retorque first. I've had a similar issue on older cars that leaked a bit in this area for years without an issue. Some makes are prone to it but, how much leaks and keep an eye on the oil/water.
Remember to loosten the nuts just a fraction prior to re torquing.
 
I had this problem with my engine before the rebuild.

The guy that did the machine work (a Triumph mechanic for 20 years now) told me that he's seen many TR6 engines with that problem and while not desirable, it's not necessarily that harmful.

I would re-torque the head as well to see if that helps before i'd rip into the engine.
 
You have three choices. Retorque the head. Change the gasket. Change the gasket and use a sealant away from the cylinders.

Many will argue that you shouldn't but I used Permatex sealant on the left side of the block.
 
I assume you don't have oil in the water & vice versa? Be sure your PCV system is working properly. I would thoroughly clean/degrease the engine & then run it to see where the leaks originate from. When I bought my TR250 the PO had by passed the PCV (gulp) valve & pressure would build up in the engine & started to push oil out a lot of places.

Repairing that is a much cheaper fix than a tear down.
 
Your oil leak could be coming from above the head or from the front and draining back along the head gasket. It might also be coming from a pressurized source and squirting on there. Although anything is possible I doubt the drivers side of the head gasket would leak oil, unless the entire head is considerably under torqued.
I would very carefully clean all surfaces on the top, front, and side of the engine and make sure they are dry. Then operate the engine for a short time and see where the leak appears and see if you can follow it to a source. It could be the valve cover gasket or the front of the engine.
 
I have a slight leak as do all TR6's in that area. Bunzil happened upon the fact that the bolts going through the rear engine lift bracket, located in the very same area, happen to go through the oil galleys going up through the back of the block. He was going to try to install the copper gaskets that are used on the galley plug at the back of the head where you would run the auxillary oil line to feed the rockers, but I never got a reply if this worked. The leak in this area would appear to be coming from the head gasket, when it actually is not.

We need a test car to try it out. Mine wail be in the body shop getting the bumpers reinstalled later this week, so maybe when I get it back I'll give it a shot if it warms up.
 
Thanks to everyone for your help. I cleaned the area, ran the car, and found a small amount of oil coming thru near the middle of the drivers side of the engine. I pulled the valve train and re-torqued the head. The two nuts in this area were almost a 1/4 turn under torqued. (They were the worst. Most were 1/8 turn or less.) I put it all back together. The weather is bad here now, so I was only able to let it idle for about 15 minutes in the shop. So far no leaks! As several have indicated, this may be more or less normal on these cars. I hope I will be able to at least wait a while before needing to pull the head. Thanks again, David K.
 
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