All Teeners!

914, 2.0, 1974, 25K miles.......All Stock


It has been a good summer so far, the 914 was running great with the exception of getting a bit too hot on a hot day. When the engine would get real hot it would not idle correctly. It would stall, etc.

Sooo, in this forum a few months ago someone commented to me that I should drop the engine and clean the oil cooler (it looked grimy in a picture I posted) allowing it to run cooler for the summer.

The engine has never been dropped and my son broke the clutch (turned out to be the clevis) so I put it on the rack and did the deed.

Click to view attachment

Click to view attachment

Well, seems that the entire car is built around the oil cooler. To get the cooler out you have to

drop the engine
Remove all of the stuff on the passenger side of the engine
Remove the Distributor
Remove the tin (why is it held in place with flat head slotted screws instead of 10mm bolts like everything else? )
remove the oil filter
remove the oil filter bracket (this was a real pistol, removing one of the nuts took an hour)
Un bolt the oil cooler (two long bolts a 1/2 turn at a time)
Oil cooler does not come out (wiggle it for 30 min)

Seems that the mounting bracket bolt was 1/4 inch too long,,,,grrrr,,,,,grrrrr,,,,,

BANG

I was finally able to get it out.......whew...........

THEN I find that though it was covered with oil, none of the baffles were dirty. They were all clear and free of grime!

I am asking this advanced group of 914 experts,,,,,,,,other than plugging the oil leaks (which were somewhat minor but getting the car and my garage dirty) what would you do to chase down a hot running 914 while the engine is out?




BTW it runs real sweet........though a bit hot.....

Here’s a crazy idea I learned over on the Pelican 944 forum...if you’re running premium gas, try mid-grade. There was a perceptible drop in temp on the 944 when we did that, with no adverse affect on engine running, power, etc... and an extra dollar or two in my pocket!

With the tin off make sure the air flap seals nicely on the rubber seal above the oil cooler. That flap should be closed with the thermostat off. Make sure there is no caked gunk on the cylinders.

etc, do you have good floor pan air deflectors...Best, Mark

Also be sure to seal all holes in the tin, and that the tray seal is good and properly installed

Why do you think it was running hot? Got the stalling when hot part, but, that doesn't directly correlate with the engine is running too hot.

Sorry if that was posted in another thread but I don't recall.

If you haven't seen it already there is another thread where @nditiz1 is struggling with a motor running really hot and lean on cyl 3/4. Much of the info over there applies.

Is timing correct . . . valves adjusted correctly, etc.
What metric are you considering to be too hot?
Air deflectors in place?
All seals in place?
Cylinder head / oil cooler / cylinder head cooling fins not obstructed?
Flaps operating properly?
Etc.

http://www.914world.com/bbs2/index.php?showtopic=347058

Funny,

I have ONE on the drivers side but the one on the passengers side is long gone. I will replace it, but could you brief me as to the it's effects?

Thank you,

Thermostat Off? Since it is a bellows and not a switch, does Off=HOT or COLD?

What a crazy but logical idea, I will drop a grade!

Thank you Mr. Dover MA

They are to create turbulence under the car to aid in moving the hot air from below the engine.

I also us 89 oct in my car. it runs just fine with it.

When the thermostat is compressed (room temperature) It's OFF,
When expanded by hot air it's ON and. pulls the flaps to the full cooling position.

Click to view attachment

When the engine is cold the air is NOT routed through the engine and oil cooler fins since it was designed to run at an optimum temperature range. The engineers set this up to heat the engine fast and then maintain a temperature range. Sooo, when the engine heats up the belows expand from a HOT state which will OPEN the Flaps and Cool the engine.

My setup for this was rebuilt when I got the car out of its 40-year hibernation. I am certain it operates correctly and remember calibrating the belows(using instructions from the Bird Site).

Nice drawing - thank you!!!

SuperHawk!

Perhaps I AM chasing 2 gremlins. The hot issue may be a phantom and the idle-when-hot issue may not be from OVER-HEATING but just from hot!

Hmmmmmmm

So, perhaps I was parinoid, but the engine temp gauge (which is calibrated to perfection! - dripping with sarcasm here) was getting close to the red (2.0 center console gauge).

Could you please comment on:

The guage and experience with it's acuracey (lack of )

as well as

Best way to measure operating temeperature (Head? Oil? Cyl?)

Thank you Mr Hawk!

First thing to recognize is the the OEM 914 gauge in the console is reading Oil Temperature.

Oil temp is a lagging indicator of engine temperature. Oil temps change rather slowly, but, will be more stable than cylinder head temperatures.

Oil temps are controversial. Many will say that 240 to 250 is way to hot for oil. This is not true especially for an air cooled engine. Water pumpers run cooler for sure. In my opinion, too many folks get focused on what is ideal for a water pumper and then try to assume that an air cooled engine should run at similar temperature. It will not.

Higher oil temps will lead to shorter oil change intervals but higher oil temperatures are not fatal on their own merit.

I'll just plop down a couple references that back that position. You may want to do your own research and draw your own conclusions but know that modern synthetic oils can easily tolerate temperatures well in excess of 250F. Just to be clear I'm not recommending synthetic as it has other implications about not having enough Zinc in Mobil 1 synthetics for our engines. Just stating the fact that modern oils can perform well above 250F. We are no longer dealing with 1970's Dino oil anymore. What was true in 1970 is no longer true about oil today.

http://haysvwrepair.com/operating-temperat...20250%20degrees.

https://www.mobil.com/en/lubricants/about-u...-oil-protection

So here is a great link to the calibrations for 914 gauges vs. sender and early / late guages.

http://www.914world.com/bbs2/index.php?sho...17496&st=20

Click to view attachment

Make sure you know what gauge and sender combination you have.

Then check it's calibration via boiling water to be sure it is working properly.

make note of the post from within the LarryM post:

"The USA 914 factory installed oil temperature gauges never included any numbers on them and the owner's manual advises that the needle will normally vary up and down within the white zone depending upon ambient temperature and engine load, but the owner is not required to take any special action unless the needle goes into the red zone."

So bottom line. If you're not well into the red, you don't have an oil temperature problem. Of course that assumes you have the proper parts for the OEM gauge and the calibration is still correct.

I'll end this post here under the assumption that your gauge is hovering near the red zone but not into the red by any significant amount.

Cylinder head gauges are another topic of their own. I personally believe that a cylinder temp gauge is worthwhile. Cylinder head temps will lead oil temperatures but are more variable based on load, ambient temperature, and what type of gauge you use (VDO vs. Dakota, or other brands). I once had a plastic bag get sucked into my cooling fan. My cylinder head temps went up unusually quickly and unusually high. I would not have detected that with an oil temp gauge until it was far too late.

SHawk, great stuff - THANKS!!!

Now, that idle problem when the engine is hot? Any ideas that I could try?

THANKS AGAIN!!!!!

I'm not the best guy for FI troubleshooting. Lot's of guys here @ClayPerrine @JeffBowlsby @BeatNavy are better sources of trouble shooting FI.

First thought that comes to mind for me is cylinder head temperature sender since you indicate the symptoms are related to engine temperature. Another very common issue is bad grounds and corroded connectors. Grounds are even more likely if you were running great at one point and now it has gone intermittent. DeOxit is my favorite for cleaning connectors.

These old FI systems are analog and depend largely on converting physical information (temperature, manifold pressure, etc.) into a resistance and/or voltage signal. Bad grounds and corroded connectors cuase havoc on passive analong sensors like we have in these systems.

The nice things is sensors can largely be verified as discrete components that are either OK (to a specification) or Not OK.

If you don't already have it download the Bosch troubleshooting guide.

From B. Anders page download the troubleshoot guide - this will download as pretty clear images of each page

https://members.rennlist.com/pbanders/VW%20...ing%20Guide.zip

From Samba - this will download as PDF but is a bit fuzzier but it all downloads as 1 easy PDF.
https://www.thesamba.com/vw/archives/manual...al_type_3_4.php

Of course B. Anders page is a wealth of info on p/n's -- make sure you're not working with a Frankenstein sytem with mismatched ECU, distributor, and sensors.
https://members.rennlist.com/pbanders/DJetParts.htm

I agree with everything @Superhawk996 said (not sure I'd mention my name in the same sentence as Clay and Jeff in terms of expertise, but I'll go with it ). I would add the following:

1. Thoroughly clean your dizzy and advance plates. Lightly grease them when you are done. Make sure the ground wire is clean and solidly attached between the plates. There are threads here about how and why you should clean it. In a nutshell, when hot the grease may start sticking and binding the advance plates which can cause issues.

2. Do you have a wideband O2 sensor? If not, it's going to be tougher to troubleshoot. Other than the dizzy and grounds and FI connections in general, you're probably running (no surprise) too lean or too rich when it's hot. Idle can stumble and car can stall in either scenario, and it is generally much easier to chase your target when you know which direction to head.