Can't get oil temp down

[chitwnvw]

Tell me if this is right. With the arm the cable attaches to facing up, when I look into the spark plug hole on the drivers side over the oil cooler I cant see the cooler because the flap is closed. When I push the arm towards the front of the bus, the flap over the oil cooler opens and I can see the oil cooler. Thats the way it is now.

That's correct. It diverts air away from the oil cooler until the engine warms up. When you push the arm to the front of the bus that's the cold position. I don't think you can mess this up...unless...

I never really thought of this until now, but if you have a failed thermostat and you hook a cable up as if to a good thermostat, you will fry the engine. Why am I thinking of this unlikely situation, you ask? Because I just reattached my cable this past weekend, but didn't check the thermostat.

[Randy in Maine]

Colin actually explains it pretty well....

[Amskeptic]

72 Kombi,

It sounds like you are taking an intelligent approach as far as your questions go. You have touched upon all likely places, but now we have to get esoteric. Your head temperatures seem laughably low for those oil temperatures (not that I trust the gauges).

Any discussion of timing or mixture is not going to answer your question here if your head temps are low, ergo, timing and mixture are not the cause of high oil temps.

Your oil cooler is clean (on the outside, no smashed fins?) you have 3.75 quarts in the system (yaah?) the bottom of the crankcase is clean (better be, make it shiny clean) and your oil temps are averaging 240*? That is perfectly OK. You want a good check of oil condition vis a vis heat? Pull your valve covers and look and sniff. If it smells acrid , the oil is breaking down. If it smells sweet, it is fine. Are the surfaces inside crusty black? Oil is breaking down. Are the surfaces caramel? You're doing OK, and if they are aluminum shiny with just a wet coating of semi-yellow, you're OK.

You might have circulation issues. The oil in the VW is doing both lubrication duty and cooling duty. You need all 3.75 quarts for cooling capacity. If you are down a quart, for example, the oil is spending more time in hot places and less time in the sump where it gets a chance to cool.

You mention low oil pressure at idle. This can be heat related loss of viscosity, yes, but in the Type 4 it suggests a couple of potential structural issues.
One is a sticking control valve, located between the pushrod tubes on the right side of the engine. This would dump oil into the sump.
Another is a possible pressure leak at the fuel pump pushrod, particularly if you have pulled the pushrod and switched to an electric pump.
And finally, you may have excessive bearing clearances from general engine wear, the flow through the bearings rises exponentially, i.e. at .006" bearing clearance, 5 times as much oil escapes as .003".

Is your head temp gauge hooked up to a loafing cylinder? What if #3 is the low compression cylinder just coasting along while the other three are are running hotter? This would give you high oil temp and lower than expected CHT readings. Might want to see if you can monitor a cylinder on the other side of the engine.
If your cylinder head temps are categorically cool (below 375*) and the oil temps are categorically high, I would have to look at frictional causes of high oil temps. Sustained high rpm gives higher frictional oil temps, but again, I come from a quarter century of sustained high rpm desert freeway driving above 70 mph in my '73 bus, and have never had an issue with oil temps. My readings (see:theSamba/Baywindow Bus Forum/ Oil Temps/Amskeptic or Itinerant Air-Cooled 2004/5) were always in the 230-260* range and I did not care. I use Castrol GTX 20-50, and I did not care because the oil always smelled sweet and the rocker arms cylinder head surfaces have always remained clean. The dipstick was pretty damn warm at the beginning of the gas stop, and would get baking hot as I gassed up, that is a natural result of heat-soak when the engine is shut off. My senses take precedence over gauges.

There are many opinions and lots of advice available to you. There are some people who draw lines in the sand about various operating parameters. I am too lazy to get excited easily. If the engine is running well, does not smell like it is in distress, if the oil drains clean and smells nice, enjoy the day.

Your most important search right now is the low oil pressure. Though warm operation is triggering the oil light, I think it is merely the symptom. The actual problem might not be "too hot" but "not enough oil pressure."
Colin
(p.s. the dieseling when you shut the engine off is a typical behavior when you have fuel cut-off solenoids that are not firmly seated. VW had to start using these things in 1968 when these engines started running hotter due to mandated emissions. Lean mixtures cause hotter combustion. You might catch a hot right side of the engine when you monitor the right CHT. Check synchronization of carbs. Also, thermostat lever, needs to seat with a clank when you release it in the "up" position. Make sure that yours is all the way back in the fully open position)

[72Kombi]

Yes, my engine is really clean and the cooler looks tip top. I am not sure what rubber shroud people are referring to thats around the oil cooler? I assume this is from underneath?

Here's what I have done so far:

1. I checked the points and timing even though the engine was just tuned. Everything looked ok but the timing was a tad hi so I backed it down a hair. I doubt it was off that much (if any) and with the degree marks long gone and a line carved in (not to mention three different pulley markings from PO) who knows. I did find the VW mark and thats the one I used.

2. The oil was about a 1/2 quart low and I went ahead and changed it out with 20w-50. Then took it out for a 45min drive in about 65 degree weather. The oil temp went up to 258 and then backed down to 250-253. I would have to assume that it will be more when its hotter out. One thing that is different now is that with the heavier oil, my idle pressure is now 5psi and not zero at the higher temps. Driving pressure was around 32 psi. If it stays this way, I'm cool with that. The engine does not smell hot or seem to be suffering when I lift the lid after reaching these temps.

3. The CHT gauge seems to be pretty close to accurate. I climbed in there after the drive and compared it to a laser thermo and they were pretty close. My gauge read no more than 345 on the drive. I suspect that the placement of the sensor is not the best and might be giving a low reading. Its sitting wedged in between two cooling fins towards the top of the cylinder. Near the top of the plug. Would it be noticeably cooler there? Just a guess. If not, I can pull the plugs and check the compression even though that was supposedly already done.

Man, things were simpler and less stressful before I put these gauges on. lol Ignorance is bliss.

[spiffy]

Get the 14mm ring to crimp onto the end of your thermocouple wire and stick that puppy under a spark plug.

[chitwnvw]

Get the 14mm ring to crimp onto the end of your thermocouple wire and stick that puppy under a spark plug.

[72Kombi]

Where do you get those 14mm rings at?

I checked my compression just to rule anything out.
#1 115
#2 120
#3 115
#4 119

So that looks fine. Im going to investigate some of the other suggestions in a few days.

[spiffy]

Where do you get those 14mm rings at?

Ratwell sent me two a couple years ago, not sure if he has them anymore. DD should be able to hook you up as well and the pic that chitwnvw posted is the what you really want to get.

[Westy78]

For future references, bad thermostat on the left good one on the right. So much for having a spare.



Don't be to comfortable with the CHT with the sender stuffed into the fins. That area is getting constant air flow. You'll most likely see higher temps when you get it in the right spot under the plug.

[Amskeptic]

timing was a tad hi so I backed it down a hair. I doubt it was off that much (if any) and with the degree marks long gone and a line carved in (not to mention three different pulley markings from PO) who knows.

You must be more specific here in IAC land. What did you set your timing to? What is the factory timing? (quiz question). What is your centrifugal timing at 3,200 rpm? Does your vacuum retard work? You must test it, no guesses (it is easy, at a warm idle apply vacuum, with your mouth even, to a known good hose leading to the retard nipple. Idle must drop and vacuum can must hold your vacuum. You CANNOT time to VWs factory idle specifications with a non-functional retard unit. What carbs are you using? No degree marks because no scale? Not allowed. This is too important for guesswork.
Colin

[72Kombi]

You must be more specific here in IAC land.

Fair enough. I'll order a new degree scale today and report back then. My Muir book says my timing should be 5 degrees ATDC. I have no idea how to check the centrifugal timing. (little help )

As for carbs, I have a weber progressive. It was one there when I bought it. I would gladly replace it with the stock duals if I had someone local to help with the set up.

What is the best way to test the vacuum retard?

[Randy in Maine]

You can test the advance by hooking up the timing light and watching it advance as the engine revs up to 3600 RPMs.

I test the retard by applying vacuum with my hand vacuum pump to see if it holds vacuum and by watching the timing light with and without the retard line hooked up to the distributor.

retard line on =5º ATDC
retard line off ~7.5º BTDC immediately.

I don't know how to make a weber progressive work well on a type 4 engine. Some people can get them to work pretty well with lots of time spent tuning. I think the vacuum signal shanges with speed or something.

I would be looking for better dual carbs if it were me.

[vdubyah73]

With your CHT sender placed where it is, ''wedged between cooling fins?'', I would suspect that your head temps are WAY HIGHER than the gauge says. I wouldn't be driving it much till this is figured out. I suspect that your head temps with the correct placement of the sender will be high and close to valve damage temps. May be as simple as timing way out, vacuum lines hooked up backwards, or vacuum leaks in the intake. Try disconnecting and plugging both vacuum lines, rev engine to 3000 rpm or so and set timing at 28-30 advance. Take it for a ride with the lines still disconnected and plugged. See what your temps are then. If they come down then it is all in the timing. Does the engine ever make noises like a bucket of marbles or the knocking kind of sound of a diesel at idle. If it does you have detonation happening because of the high temps. Detonation will ruin your engine toot sweet. Too find out which hose on your dissy is advance and retard, Put a piece of vacuum hose on first one of the vacuum can nipples and then the other, then put it in your mouth and suck on it while engine is idling. If idle goes up, that nipple is the vacuum advance hook up. If the idle goes down, that nipple is the vacuum retard hook up. I can't figure an easy way to determine which nipple on the carb is vacuum advance or retard on your carbs, I'm not familiar with ...... Wait a minute you have a Weber Progressive! is there even a retard vacuum port on the Weber progressive? Figure out which is the retard vacuum line for your dissy with the suck method and discard it. Where do you have the 2 lines hooked up for vacuum? This may be your only problem. Lets sort out the vacuum lines before you go buying anything.

Bill

[72Kombi]

Ok. I ordered the timing scale and it will be here next week. Im not going to drive it or fool with the timing until I get the scale in place.

vdubyah73, to answer your questions:

The engine does not ping, knock, or sound like a diesel. Ever. And yes, the weber does have a vacuum port.

I have a digital timing light that displays the advance but I need to figure out how to use it.

When I get the scale installed Ill start putting all this advice to work and see where Im at and report back. =D>

[chitwnvw]

If there's only one port it's an advance port, if you had two then you'd have an advance and a retard port.