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Triumph TR6 - Diagnosing heavy oil consumption
|John here, not as old as some, but older than many. I've learned a lot from you older and wiser folks in the last 3 or 4 months. Lots of little things have been fixed. Now, I want to figure out where my oil is going. It isn't leaking onto the ground, but some was seeping out from one of the valve cover bolts--I think I fixed that. The smoke doesn't seem to be excessive.|
Could one of you nice grandfatherly types tell a young fella what steps to go through to diagnose this problem? PS, I sort of presume it is valve guides, but don't know.
|John (you whippersnapper),|
Just how much oil are we talking about here?
How much do you burn/lose in how many miles?
If you steam clean the underside of the car then you will KNOW just how much it's leaking when you drive down the road. That is, maybe it's blowing back onto the underside of the car and a lot of it is 'blowing in the wind'.
Let's start there. Is the compression good in all cylinders? Just curious.
|Back in 1958 when I bought my TR3A, Standard-Triumph quoted 600 to 1000 miles to a quart of oil. I used to keep mine as close as I could to the top line because I thought more oil would stay cooler longer, therefore it wouldn't burn as readily. A fellow TR3A owner from Houston told me that he keeps his level to the bottom mark on the dip stick. Too full and it gets blown out.|
So for the last 3 years I keep the oil level near the bottom mark. When it gets to the bottom line, I add 1/2 a quart. Also I use 20W50 now. Before I was using 10W30. So my oil consumption was reduced from 600 miles to 1000 miles per quart.
I also heard that about 10 TR6 owners at the same event were discussing this and someone proposed they all go and get their dip sticks (No! The one from the TR6) and they laid them all out beside each other. Believe me, SIZE IS IMPORTANT ! They were all so different, they couldn't believe that all these dip sticks they were looking at - all from TR6's - were so different. Low level in one TR would have been overfilled if he put it in another TR6.
Maybe there is something to it. Better get to know the gremlins in your TR, otherwise they'll get you !
Don Elliott, 1958 TR3A
|John - You may have mentioned it before, but do you have the stock or aftermarket valve cover? Regardless of the carbs, there is no baffle on the "aftermarkets", so alot of oil gets splashed up and blown out. |
| I did a rebuild and my oil consumption dropped to almost zero, my oil loss is a different story. They all leak, some more than others. I don't worry about a leak until it starts getting whipped up in the draft and deposited on the rear of the car. Check the level often, use 20-50, change it often, and change the filter every oil change. You know it's leaking bad when they quit tailgaiting you.|
|I think I have the stock valve cover. The actual consumption/loss is about a quart in 300 miles. It does not appear to have any major oil leak underneath, or at least I don't see it on the garage floor. There has been some oil on the underside of the bonnet (oh how veddy British of me), but that got better when I tightened the valve cover bolts a tad, not enough to mess up the valve cover. It doesn't appear to be leaking at the valve cover gasket. As for steam cleaning, I don't have the equipment to do that.|
An easy "test" is to route the hose from the valve cover breather to a bottle for several hundred miles and see what accumulates. Stuff a rag loosely in the top to help filter out some of the stuff.
I seem to recall that you had SU's instead of Strombergs, and the hose goes into the air filter housing - is that right? Be sure and plug off that end, or the carbon cannister, if that's where the hose goes.
That temporary set-up will quickly give you a feel for how much oil is getting burned by that route. It turned out to be very significant on my car with a "Triumphtune" valve cover - 6 to 8 oz every 100 miles or so. With an add-on internal baffle it's been reduced to maybe 1 oz/150 miles.
|A quart in 300 miles is indeed excessive.|
I like the baffled/non baffled rocker cover idea and Brent's deal with the catch can.
That oil is going SOMEWHERE methinks.
|Maybe the goose is getting my oil. Brent, if I route the breather hose to a can instead of into the air filter, is there any danger or adverse affects possible? I guess from what you're saying that I could route it to a can, and see if there is actually oil in the can? If there is no danger, I will try it. |
By the way, is the purpose of feeding the breather hose back into the air filter assembly to burn off unburnt oil and vapors? Or what? Thanks, John.
|John, John, no dangers whatsoever other than to the goose.|
The can thing is perfectly safe. The only thing that will happen is you will reduce smoke (if that's the issue) since the oil that was previously being pumped into the intake and consumed will now be going into the catch can and NOT into the intake via the aircleaner can.
If that IS the case then perhaps we have a case of excessive crankcase pressure causing oil to be carried into the air cleaner can.
An interesting experiment would be to plug that hose coming from the valve cover and, with the engine warmed up and idling, remove the oil filler cap. If there is a great deal of pressure that escapes then we know we DO have a crankcase pressure issue and we can suspect rings being the culprit.
Have you done a compression check with and without oil being squirted into the cylinder being tested?
Take a compression reading of a cylinder. Warm engine, coil wire disconnected, engine cranking over (strong battery helps) about 6 times with throttle full open, choke open. Record the reading. Now squirt several squirts of motor oil into the cylinder and check the compression again. If the compression reading goes up then your issue is certainly rings (the oil has caused better, temporary, sealing of the oil control ring and compression rings. If the compression is 120 or so (varies a bit either way is fine) and the reading stays the same after you squirt oil in the cylinder then you're fine. If we have a cylinder that is considerably lower, say below 100, and the oil doesn't make a difference then a valve may not be sealing properly.
100 and up you're ok generally. We want as little variance between cylinders as possible. 10% variance is generally considered nominal. More difference than that and I will go looking if it's my engine.
Again, the oil squirted into the cylinder will raise the compression reading if you have a ring problem. It will make no difference if you have a valve issue.
I hope this helps,
|Yeah - no danger from fire or explosion, if that's what concerns you. Don't drop the can the fan - it may fly back at you. The gases are largely exhaust blow-by from around rings and through exhaust valve guides - pretty obnoxious to breathe them, but not flammable. And unless you vent it into the cockpit, shouldn't be poisonous.|
The venting can entrain oil out the breather, so if it's a problem you'll see a bunch in the bottom of the can within 100 miles or so. You can pour it back into the engine. If you don't see any the excess consumption is probably mechanically related. Have I told you about the garlic jar...
|Jim and Brent, thanks. Some comments: 1. Wouldn't the excess oil show up in my air filter assembly?--there didn't seem to be any when I had it apart and changed the filters a month or so ago.|
2. The compression was 120 across the board when I had it checked in August. Does that mean valves? I kind of suspect the valves/valve guides from what you guys and others have said.
3. Brent, can I use the can without a rag in it? It seems to me that the rag would soak up a lot of oil. Also, does the rag go in the top of the can?
Thanks. I have a 4 day weekend coming up, although I promised my 21 year daughter who is home from college that I would teach her to drive the TR6 with manual. Happy Thanksgiving to all! John.
|JL - if the line goes inside the filter I wouldn't expect to see any oil there. And sure, you don't have to use a rag at all. I put one in the top of an old radiator overflow bottle mainly to keep the hose in the bottle.|
|JL - Here's to hoping you solve the oil consumption issue at minimal cost and hassle; and that with your pending Thanksgiving task that you don't show up on the "Clutch Rebuilding" thread|
|Laughing at Steve and the "clutch rebuilding" deal. Well said Steven.|
If the compression is 120 across the board then you're probably ok, assuming the compression test was done properly. Compression testers are reasonably priced though and would be a fun thing for you to learn how to do.
Valves not sealing to the valve seat can cause low compression.
Valve guide wear can cause smoke (usually when the engine is first started up or just starting out) and a slighter amount of oil consumption than what you mention. Again, 300 miles to a quart is VERY MUCH EXCESSIVE. It's a lot too Bud. Not only that but it would drive the goose out from under the hood.
Now. I'm holding out for a leak. I'd love to know the difference between your compression numbers with and without oil being squirted into the cylinders. That having been said, 120 on all of 'em ain't too shabby. I'd be happy with that if mine weren't at 125 across. <G>
Sigh, I just had a call from my buddy who stores my 6 in the winters for me. He had to move it to 'adjust' positions of some cars (I trust this guy implicitly) and he noted a 'clunk' when he moved the car fore and aft. He's VERY knowledgeable about TRs and the noises they generate.
Anybody want to do a rear end mount for me? I am SO not looking forward to that in the spring.
Sic 'em John.
|Jim, you'll really be proud of this very young whipper snapper (compared to you, but unfortunately not to the average on here). I got a set of 4 jack stands at Sears today. Now I can figure out how to stop that transmission fluid leak and take a good peak under there to see if I can spot the oil leak. While we have more than adequate disposable income, my wife has been a real trooper about this! Sometime this weekend, I will see if I can figure out the can trick and I will crank the little car up on the jacks and see what I can see. Happy Thanksgiving to all. John.|
You probably know this, but one shound never get under a car on jackstands with the engine running. Period. Vibrations can make things walk. Peek in from the side.
|What BRENT SAID!|
|Gotcha, Brent. I wouldn't think it to be a good idea to even start a car while it is on jack stands. John.|
|Hey, Jim and Brent--here's another good one I notice today, courtesy of the "Jaguar Expert" that will never touch my car again. The fiber washers on the valve cover bolts are all missing--maybe thats why oil seeps out there. That guy really ripped me off-the carb linkage was screwed up by his people, one of the 2 gaskets between the air filter assembly and the carbs was missing and now I've found the fiber washers aren't there. He replaced my rear axels and I sure hope that was done better than the work I can figure out so far! John. Hope everyone had a wonderful Thanksgiving, by the way. It was about 80 degrees here and beautiful.|
Welcome to that's my Triumph/Baby/Dog/Mistress/Wife there BUDDY.
DON'T MESS with any or your next stop is Canada...:)
John once you get into your TR. No one will ever pay as much attention to its fine points quirks and details as you do. If you've read 1/10th of the archives here you probably know more TR. theory than Mr. Jaguar expert ever will?
BY the way its a nice round 0 degrees here in Southern Ontario. No Turkey here, even the edible geese flew south. The big fat white slush is falling steady.
Hope all Southern friends are having a great Thanksgiving! I ducked out early from work to play at the shop today. So I had a salomi sandwich for supper because I came home late. Wifes funny about that?
|When Bill talks about it being zero in So. Ontario, he means zero Celcius degrees which for our US friends is equal to 32 degrees F.|
Did you know that F is for "Fahrenheit" ? Did you know that the Fahrenheit scale was devised in Germany by a German ? Bavaria actually. He chose the coldest day in winter in his Bavarian valley to be zero on his scale and 100 degrees to be the warmest (hottest) day in the summer in his Bavarian valley. And when the mercury went up or down in the closed glass tube representing the scale he had devised, he knew what the temerature was in his own Bavarian valley.
And everyone says that all you can do with the weather is talk about it.
Don Elliott, 1958 TR3A
|and that celcius and fahrenheit actually MEET when it's -40 degrees.|
And that's MY contribution.
Jim (keeper of the goose)
This thread was discussed between 20/11/2003 and 30/11/2003
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