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Triumph TR6 - Fouled plugs

My engine was completely overhauled, however the plugs are oily. Other than bad rings, pistons, valves, etc, can the problem be something simpler?


E. Wong

Hey, Gene.

If the engine was JUST rebuilt the rings probably aren't matched up to the cylinder wall yet, which could be a source of oil. That should go away after a "break in" of 1000 miles or so.

Brent B

If you had someone rebuild your engine, they would be the best to talk to. I've never had oil on the plugs after a rebuild, maybe a little more oil consumption than after 1000 miles, but never enough to show on the plugs. Does it smoke? I would think it'd be smoking like crazy! Tell us more about how the car runs.

Bad news for me. I took it to a British Car specialist and he suspects the rings have been installed incorrectly or the wrong rings have been used. The top of the pistons are wet and the plugs are fouled. Also, the oil pressure is abnormally high. Oddly, the car only smokes a little on start-up. Once warmed up the smoke disappears and the engine runs decent. I'm really confused...and stressed now. I paid top dollar for my restored TR.

Hi Gene

First off everybody these days is a bloody specialist. That engine was also used in farm machinery. And from what I've heard so far your local tractor dealer would probably be a better bet for getting it fixed?

If the last outfit was not refered to you by your local Brit. car club run. From what you've posted run anyway!!!

You oil is coming down from the head in my estimation. If after running for a bit the oil problem goes away?

Bad rings or wrong rings will give you smoke all the time. If the oil is passing the oil rings coming from the bottom end it will only happen when the car is running and burning it off. Smokin!!

Enough to give you oil on piston tops???? That engine would have to be so loose no amount of warmup would let it run without looking like a bad deisel if it ran at all.

Yep high oil pressure will do strange things things but the wrong rings won't cause high oil pressure at the gauge.

OK considering the engine was rebuilt.

My guesses at this point would be some or maybe all of these.

Only possible thing I can think of that could do all that by itself would be an improperly installed or wrong head gasket. They should look at the top end oiling for flow and drain.

Valve stems but not likely.

Your oil pressure relief valve is faulty? If you have an add on top end oiling system combined with that your valve cover is full of oil.

After market spin-on and external oiler faulty.

Thats a few ideas. I can think of a lot more. Yep someone screwed up somewhere but it wasn't the rings.

First find a good garage. Post your area someone here can recommend likely. Have the compression checked. Just incase I'm out to lunch...:) No that is always the first thing checked when theres problems on a rebuilt. Make sure the crankcase is ventilated. Double check oiling system including whats coming up and flowing away at the top end.


Bill Brayford

Thanks for the great input. Since the car isn't smoking, the rings/pistons must be o.k. Maybe my specialist has been smokin instead?

My oil pressure is around 50-60psi at idle but rises to 85-95psi at speed. This seems too high. I also noticed oil oozing fronm the dipstick. Is it difficult to change the oil pressure relief valve?

My oil pressure is 50 -60 at idle and 90 - 100 on the highway increased when I replaced the oil pump, main and crank bearings ....basically the same readings as yours but without the other symptoms.
Charlie Ballard

Hi again,
I forgot to mention that it's easy to change the valve, as I recall the Bentley book tells you how to check it and measure the spring. If you don't have the book I can get the info for you.
Charlie Ballard

Charlie, thanks for the info. Your situation sounds exactly like mine. How many miles have you put on your rebuilt motor?

This thread was discussed between 30/09/2004 and 04/10/2004

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