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Triumph TR6 - Oil spewing out of dipstick opening- why?

Hello fellow TR6ers. Well another problem for me.

Yesterday on my 210 mile drive, the oil pressure dropped. A quick stop revealed that the oil sump was almost empty (and it was full when I left). There was oil around the dip stick area. I filled up the sump and got the car home.

Today in troubleshooting- I noticed oil burping up the oil dipstick chute and out.

Some other history- I have always had a small leak around that area and always thought it was coming from the seam where the chute is pressed on the block. The leak was annoying but amounted to a liter of oil a after 1000 miles or so which I lived with. Last year, I replaced the timing chain cover oil seal and the spacer it sits on because that was leaking a bit. Before I took the car out this year, I fashioned up a gasket to seal the seam where the dip stick chute is pressed at the block.

One or both of these changes has caused the leak to substantially increase it seems.

It think the crankcase pressure might be too high.

Another thing to consider is - I have jury rigged a PCV system by using a North American PCV valve since the original PCV valve was removed some time ago.

Anyone with any experience with oil burping out the dip stick or with too high crankcase pressure and what you did to correct it? Is my jury rig not allowing enough pressure to vent?

Appreciate your help and suggestions. Thanks.

Mike Petryschuk
69 TR6

Michael Petryschuk

Did the problem start after you fitted the new PCV valve? I'm not entirely sure how the Triumph PCV worked but it was removed on later models. The TR6 is an "open" design so if there's anything that prevents the engine from venting through the valve cover vent then the pressure needs to be relieved somewhere, perhaps in your case the dipstick tube? Have you considered running without a PCV to see if that resolves the problem?
DW More

Not sure why you have pressure in your crank case. As you know, your 69 should have virtually no pollution control stuff. I wounder if this PCV is causing you this pressure?
You should not have oil comming up the dip stick tube. There is a felt washer on the dip stick itself. Is yours missing? I am sure unlikely, but, Is your oil level too high?

Also, I had an oil leak around the base of the dip stick tube. I put some "putty weld" around the base and painted it black...invisible and no more leak.

Rick Crawford

If the pvc valve is backwards the crankcase won't breath and pressure will build up. Take off the valve and shake it, it should rattle if it is not plugged up.
If it is plugged, either get a new one or like DW said, go without.

rw loftus

Mike your not running an external oil feed are you?

Thanks for the suggestions.

To Answer DW- I have always had a small leak in the dipstick area since putting the car on the road after it was off the road for 20 plus years. I have had the jury rigged PCV since I put it on the road and never thought that too high crankcase pressure may have been causing the oil leak. The leak has became a lot worse since I installed the new timing chain oil seal and sealed and gasketed around the dip stick tube/block seam.

As Rob Suggests - Yesterday I pulled the PCV and confirmed it wasn't plugged. I don't think it was backwards but now I will take another look at it.

Rick -the felt washer is there. Oil soaked but there.

I was thinking as DW to run without the PCV and see what happens or put a larger one in. I will report back on my findings.

A look through the archives suggests excessive blow by on the rings may also be a problem causing excessive pressure in the crankcase, but I don't seem to burn oil (no blue smoke) and the rings are new in 2005. I will be doing a compression test.

I read something about a leakdown test that requires a compressor. I do not know this procedure. Can some one help here?

In the meantime if there are any other suggestions, please keep them coming in.

Michael Petryschuk

Seems I was commenting at same time as Don- No external oil feed installed.
Michael Petryschuk

Don, as you know, a compression test measures how much pressure builds up in the cylinders whereas a leakdown test measures how much pressure leaks out of the cylinders. With a compressor and the leakdown tester you can find what percentage pressure is leaking out of the cyliders and what is causing the leak. You hook up your compressor to the leakdown tester which has been screwed into a sparkplug hole at tdc. If you have 100 psi going into the tester, but only 75 psi coming out, you cylinder has about 25 % loss of pressure, not good. By listening at the carbs for air, you can tell if it is a leaking intake valve, air at the oil filler cap will be rings, exhaust pipe will be exhaust valve and if the head gasket is leaking you should see air bubbling out of the rad cap becaust air is pushing through a leaking head gasket into the water jacket. Doing all 6 cylinders will tell much more about your engines health than just a compression test, a leakdown test is much more specific. A lot of shops don't know what it is and will think you are talking about a compression test. Princess Auto has them for about $80.

rw loftus

PS, if you break apart an old sparkplug, you can then make an adapter that will fit an air line and do the test without the tester, you can still pinpoint a problem, you just won't know the extent of pressure loss.

rw loftus

PPS Michael, my appolagies, I wish this had an edit feature, it can be embarassing without.

rw loftus

I believe I have found the problem

It seems it is the PCV system. I have it installed- oil spews out. I remove the PCV system and allow it to vent to atmosphere- spewing stops.

I plan on running it without PCV valve with direct connection to air breather fitting and we will see how it goes.

Thanks for the help.
Michael Petryschuk

This thread was discussed between 26/04/2009 and 01/05/2009

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