Running Hot.

I have a '71 Fuel injected Squareback. It's running hot,burning oil, and I can't figure out why. The compression is good. The valves are gaped correctly. The dwell and timing are set. The advance works. The Voltage regulator works fine. And the seal on the Manifold Pressure sensor is intact. I did Muir's resistance checks of the temp sensors and they are in range.

What could it be?

Reply to
Mark Healey
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Precisely what is the Oil Temp? At what road speed?

Speedy Jim

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Reply to
Speedy Jim

I smell it burning. No means to actually measure it.

Surface street driving.

Reply to
Mark Healey

Did you check the fan to make sure that there was no debris inside and it has a good fresh air supply with an intact rubber boot? Without the boot the fan might draw in heated air from the exhaust.

Also you could check the fuel pressure, if it is low then it might be running lean.

Oh and what is the temperature where you operate the SQback?

Just some thoughts!

Reply to
dave AKA vwdoc1

Then you'll have to start at the beginning. Check the thermostat for opening and that the flaps work correctly. Less likely, a problem in the oil cooler control valving.

Strongly suggest getting either the Bentley or Haynes manual.

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have some help.

You can buy a digital temp gauge intended for kitchen or BBQ use which has long, thi n probe that will go into the dipstick tube. Very inexpensive and no permanent mounting needed.

Oil temps are normally not above ~110C even at hiway speeds.

Also, look for small, hidden oil leaks. A tiny drip on hot exhaust will make the engine "smell" burned.

Speedy Jim

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Reply to
Speedy Jim

Being an aircooled motor, and having checked most of the other easy stuff - I'd make sure you have air flow where it's needed/should be, ie, when we got and started working on the youngest's '67 T.1, after cleaning up all the obvious needs-fix'n from the previous owner we still had a heat problem - didn't have a temp gauge but by the nose it was running way too hot. The major tipoff was seeing some crispy'd field grass hanging out of the bottom side tin. Pulled the motor, pulled all the tin off... seems that a) a mouse had decided to build a nest in the fan shoud to the left of the DH, meaning 3/4 were cooking in their own juices, and b) the previous owner never thought about where all those dropped nuts, bolts, screws and 1/4" drive sockets where ending up (hint: there was almost no flow btwn the cyls because of all the contributions). Bottom line: cleaned the choss out, ran wire btwn all the cyl fins, likewise btwn the head fins... and now the oil sits happily in the 85-90C range. YMMV.

greg

Reply to
greg mushial

Smelling burning oil isn't the best clue because it could be from oil leaking onto your exhaust.

So you have to measure the temperature of the oil.

OTOH, if you hear oil boiling in the case, have smoke belching out of the oil filler, well then you have a rebuild to do Real Soon Now.

And maybe, just maybe your sniffer ain't up to par and you have gas in the oil. Not good.

Reply to
John Boy

John,

Have to agree - the nose isn't the best nor most accurate temp sensor... would much rather have a real oil temp gauge... but after

40++ years of wrenching on motors... it doesn't make a bad early warning "sensor" (pretty good at: something doesn't smell right, or, something smells different - need look into it).

enjoy, greg

Reply to
greg mushial

Got the thermometer and did some highway driving. When I pulled into a gas station I saw smoke coming out of the windshield vents. I drove to the grocery store for about 20 minutes and drove 10 blocks home. I then measured the temperature and it was only 184F (85C). I'm wondering how accurate that is. The probe is about 8 inches long and It only had oil on the last 1.5 inches.

The fact that smoke was coming in through the vents makes me think that one or both of the heater boxes has a leak. I hope not. Those things are expensive.

Reply to
Mark Healey

85C is barely warmed up. Normal hiway temps can be 110C without worry.

Try this: Engine idling. Block off exhaust tips (rag, etc.). If engine stalls, there is no leak. If there is a leak, you will be able to pinpoint where.

I'm more inclined to think there is oil dripping on hot exhaust somewhere.

Jim

Reply to
Speedy Jim

Yeah. That's what I told you.

Reply to
John Boy

heater boxes can get oil dripped into them that will then burn....fix oil leaks and this problem goes away.

Reply to
Joey Tribiani

Hi, Just a suggestion. I,ve fixed up leaks in both my SB heat exchangers. One can bend, or rather unbend the sheet metal suurounds to allow exchanger to come out. I then had welded up a small leak plus some other areas that looked dodgy, "built up". Then reinsert exchanger, rebend tin and off you go. There was a spot weld up the front I had to drill out from memory. Bit of a fiddle but does save megabucks. Cheers John

Reply to
John

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