I have had problems with High oil temps (240f) since I have owned the car when if I hit the highway for any period of time. It appears that I'm not able to cool the oil when at higher RPMs (above 3000) and the out side air is not cold. I have read every post that comes up in a search about oil flow and temp.

My car
1. 1976 2.0 D Jet cal with cat, pump and other extras removed
2. 20w50 oil
3. car runs very good and smooth (I don't have any other 914s to compare to)
4. idal good and steady(1100 cool, 950 warm)
5. no oil leaks

I have added the following gages to better monitor this problem
1. Oil temp gage
2. Oil pressure gage (pressure >70psi at initial start, goes down to about 15 at idal and oil temp about 200, when oil tem goes higher pressur goes lower than 10 psi per 1000 rmp)
3. wideband 02 (12.5-13 at steady speed, goes down to about 10 at WOT for a few seconds then climbs to 11+ untill steady speed then about 12.5) (will go high 14+ for about 1 second at WOT while passing thru 3700 RPMs then back down to 12.5)

I have checked or done the following work
1. adjusted/varified the valves, timeing , dwell, TPS
2. Injectors cleaned and flow tested (made motor run much better and smoother)
3. MPS hold vacuum
4. I have done all of the ECU Ohms checks
5. I have varified that my flap is coming down and covering the Oil cooler
6. I have no debris on the cooler or air flow to the oil cooler
7. I have all of the tins on the car, I have the 2 plastic air dams under the car
8. The fan is not missing any blades but does still have the pump pulley atached(I plan on removing when I take the motor out)
9. I have installed the higher oil relief spring and valve (problem did not change)
10. I have learned a lot about D-Jet theory
11. I'm still having fun but would like to be able to drive it more


Any other suggestions would be appreaciated.

I have the same car. 1976 stock 2.0 D-Jet. Notice Porsche changed what they consider to be too hot when the introduced the 2.0 by changing where they painted the red on the gauge. In my opinion the engines are over built to as far as they could with a production engine.

I put a cheap external cooler next to the tranny on the passenger side - these kits abound on VW vendor sites. No fan and back there it isn't any too cool, but it is enough to get rid of the problem for me.

I don't see where you verified the oil temp. New gauge doesn't count.

That's an old wive's tale which is unsubstantiated by empirical measurement.
In fact, the beginning of the red zone represents 300F with either gauge when combined with the factory sender (039.919.268).
If the oil is getting that hot its not a good thing.
The problem with the early gauges is that the resolution was inadequate.

The EGR is there in the '75-'76 cars to control combustion temps. Removing it is shooting yourself in the foot, temp-wise, as the leaner mixtures in those cars tend to run hotter.

The Cap'n

Front mounted oil cooler should have been an OEM feature.


KT

To say the motor was over built as far as they could go with a production engine is just malarkey.

You drive a 2056 and jake has built some big motors with this basic platform many times.
A 2.4 motor running stock djet or ljet while still. Running cool and performing quite well is simple to build and really a great extension of the platform.

Vw built these motors to last, so they left loads of room for improvement, but at the sacrifice of efficiency.

To this day I am still fascinated by a package that can be removed as a unit, and bolted into another car, so simply it's amazing.

Easy to fix, tune, and troubleshoot...parts are still cheap for basic maintenance and if you look at the roots of the beetle with 20mm units built, it's an cool piece of engineering.

Looking at the Subaru, to me at least, is the natural extension of the vw 4 cylinder platform.

Gunny,

If you are dealing with temps that make you concerned, I would suggest you consider putting in an external oil cooler.

Thanks for the info. I have both. I should have checked.

I think I wasn't careful enough. Back in the day I was in college and I never knew of a bus with a reasonable air cooled engine life. The owners weren't going to the races, they were going to the work on the Seattle freeways burning up two liter motors. This matches my own readings of posts here and service manuals, and in books. I think it extends over to Porsches, which at the time did not enjoy a reputation of owner satisfaction regarding reliability. If you follow the nine eleven they got to a point where head and engine cooling was an issue that would have been surmountable at two liters but was very hard at well over three. So I think our engines are a bit finicky at two liters. That last sentence. I had trouble with oil cooling with a stock worn engine and I am having trouble with oil cooling with a mildly modified engine.

Jake charges what even in dollars as old as I am would have been more than porsche could have afforded, so I meant to exclude him and other people who can hand build. I was driving my tr6 yesterday. I hand built that car with every bolt. But I was driving it to visit the 914 I feel more secure in the teen, and now it packs more muscle. No knocks intended. Or wanted, sigh...

Theoretically, can you bring oil temps down a little by enriching the mixture, perhaps with a 100 ohm resistor between the CHT and the ECU? Don't know if this would make a significant difference in oil temps, though.

Beyond the fan blades, what have you looked into with the cooling system? I would start with what the Capt'n mentioned and then look into the cooling system. All the way down to the fins on the heads and cylinders. Many times rodents will nest in the engine tin causing temp problems. Bellows working fine? Cable attached and operating the cooling ducts?

Have you checked the two air defectors under the car? By driving with/without them I found out that they lower the oil themp on my car by about 10f when cruising in hot weather. /Lars S

Here in Oklahoma my home rebuilt 2.0 D-Jet is runing around 220 most of the time. It takes awhile to get there but that's where the oil temp lands. I have an aftermarket VDO gauge which I verified with a IR thermometer (from HF) reading off the bottom of the filter and the sump.

I'm using Royal Purple HP and sent an email asking about oil temps since I will get temps of up to 250. They said the oil will perform fine for extended driving at that temp. I asked for specific "do not exceed" temps for the oil but they declined.

I'm still looking for lower oil temps but I got less worried when I read that VW/Porsche set their redline at 300F.

Sometimes I think those numbers on the gauge just make us non competitive drivers worry more...and we love it I guess.

My biggest effort to get lower oil temps for the last few weeks is to wait for Fall to bring cooler weather.

Gunny...I have the same problem with my car. At the suggestion of someone else on this board, I sprayed the oil cooler from the underside upwards with brake cleaner then compressed air. Also, as an experiment, I switched from Brad Penn 20/50, to Brad Penn 10/30. Car now runs at least 15 degrees cooler. The Captain says that I'm inviting oil pressure issues but I've been driving for a month or so with no problems. It's worth a shot!!!
Good luck...

I have a 75 that had similar high oil temps issues. It has an auxiliary oil cooler with a fan mounted on the backside controlled with a thermostat to come on at 180F. I still had problems with oil temps reaching 240F. I put a vent scoop (2 2/2") on the passenger side rocker panel that channels air through a hose directly onto the auxiliary oil cooler. The aux oil cooler has "fins" on each side to help direct the air. That did the trick! My oil temps are now consistently in the 210F range with oil pressure at 40psi @ 3400 RPM (75 mph). Even on steep hill climbs it may get to 220. Prior to this set-up it would climb to 240F+. Idea came from Chris Foley at Tangerine Racing.

I had a similar problem with my 75 1.8L. It has an auxiliary oil cooler with a fan mounted on the backside controlled by a thermostat set to come on at +180F. I was experiencing oil temps of 230-240F consistently. I solved the problem with a small air scoop cut into the passenger side rocker panel just ahead of the rear wheel. It has a 2 1/2" flex hose that is routes fresh air directly onto the auxiliary oil cooler. The oil cooler was modified with flared sides to help direct the air. Now my oil temps are at 210F. Oil pressure is 40 psi at 3400 RPM (at 70 mph). Chris Foley at Tangerine Racing suggested this set-up and it worked well for me.

Today I took the motor out to take off the tins. I found a few things.

1. I removed the air pump pulley( hope I get more air)
2. I removed the pile of debris on top of the driver side of the motor.
3. I cleaned everything, tins, cylinders, all air passages.
4. I found that the heat exchangers have many many many leaks.( need to plug the holes)
5. I found that I don't have flaps on the bottom going to the heat exchangers, and did I say my heat exchangers have many leaks.
6. I plugged the flow of air from the fan housing going to the heat exchangers using sheet aluminum from a diet mt dew can. Hope I get more flow over the oil cooler.
7. Top Flaps work good.
8. Replaced the intake gaskets, intake runner to plunimum conection, oil tower gasket.
9. I removed all of the wire harness and cleaned them all, all are still in good shape not brittle.


Before the motor goes back in the car I'm going to replace the clutch. I have all of the parts.

I'd drop #6 off the list and just get the right parts and put'er back together.

Aside from being aircooled, they are oil cooled and fuel cooled.

So, the oil cooler needs to do its job with proper air flow.
You can position the flap to always be putting the most air into that cooler...you like in the desert.

For fuel, these cars are designed to run rich, it helps keep the motor cool.
Timing and a slightly rich mixture, along with proper air flow will hopefully solve this.

Acorns and nests are just all part of the pleasure of an aircooled car.

rich

Eric,

These are my thoughts on that,
because I have so many leaks in my heat exchangers even with the heat control boxes closed I am loosing a lot of air out of the leaks that could be used to flow over my oil cooler. The flaps that are missing on the bottom of the shroud would be open all of the time due to the leaks in the heat exchangers so I blocked off the air to see if it helps with air flow to the oil cooler.

If this fixes my oil heating problem I will replace my heat exchangers with a good set from an older style (I have the 76 setup).

Reminds me of the old Lotus turbo advertisements of "charge cooling". (Paul Newman era). I read that they may have had charge cooling but they were still hot as a pistol. I agree, I found that fueling and timing are really important. We get maple leaves and little boxwood pellets but not so many acorns. Fortunately the ground squirrel prefers my wife's mini van hood liner.

Gunny, just for my curiosity, are the two air deflectors under the floor, just at the rear floor edge in front of the engine still there?


/Lars S

The heat control boxes are still in place and they work, even with them closed air is flowing thru the heat exchangers out all of the leaks where they are supposed to be welded to the exhaust and one has a split in the sheet medal.

I was thinking the same way, That is why I checked the air fuel mixture by adding the wideband sensor. I was a little lean but know i'm running 12.5 to 1 at steady speed.
I have checked the air flow around the motor and only found a small amount of debris on the top of the driverside cylinders. I have been leaving my flaps in the hot position all of the time, I'm in Alabama.

I think I'm not getting enough air to the oil cooler. I have all gromets in the tins and all tins are in place.

I'm hoping that blocking the air to the heat exchangers will force more air to the oil cooler. I will find out when I finish cleaning everthing and put the motor back in the car later this week.

No Gunny, I dont mean the heater control boxes but the plastic flaps, one on each side, they really help cooling when cruising. They came with the -73 (2.0 at least) and all cars after that should have them.
Pls see this thread for explanation: Deflectors


/lars S

Yes I have them both.

Good, then i can relax!


/Lars S

Pictures we need pictures!

Thanks

That's what I'm thinking, I wouldn't have to do one.