Does that look like a plug that is running lean?

[KS]

First rule of any odd oil temp readings: change the sender. Second rule: change the gauge. Then start looking for deeper problems.

Oh, and make sure you haven't got a rag or anything (bird, small child, etc) sucked into the fan...

[jb]

When I was unsure of the accuracy of my oil gauge I used my laser temperature gun (<£20) to check the oil temperature and the gauge was correct so I added a front oil cooler.

[mycar]

Oh, and make sure you haven't got a rag or anything (bird, small child, etc) sucked into the fan...

This may well be an avenue to explore. After you've ruled out flora and fauna, check the fan itself. Is it 28 blade fan or the earlier 16 blade type ? Are all the blades present and correct or has the fan been damaged at some point ? Has the mounting hole in the center of the fan been rounded so the fan can rotate on the generator shaft.

If you fancy having a look the manual says...

Disconnect cables going to generator, take off V-belt (remove outer pulley half), release generator mounting strap" (the steel band that goes around the generator with the single bolt holding it together), loosen fixing screws on both sides of the blower housing. Raise housing slightly, loosen fixing bolts and nuts on generator support, loosen 4 screws on blower housing cover and take off generator.

The oil canister will have to be disconnected from the fan shroud as well.

[Splitpin]

I would check voltage stabilisation first, being an electrical gauge.

[neilbardsley]

I have a laser temperature gauge and the fan is the 28 blade one

Sent from my MotoE2(4G-LTE) using Tapatalk

[mycar]

So if I understand this correctly, you are concerned about a perceived sudden and rapid rise in oil temperature as displayed by the gauge on the dashboard when the engine goes beyond 3.5k revs ?

Can this effect be proven by measuring the oil temp with your laser thermometer ?

Maybe the problem here is not actually a problem per se, rather more an inescapable characteristic of the industrial engine.

Porsche industrial engines were designed to be low rpm, low load engines and never intended to spend much time over 3.5k.

Have you considered fitting a rev limiter ?

[neilbardsley]

I'm 100% sure it isn't the industrial engine as they where chosen by the builder because the case/bits weren't put under much stress. All the weak bits were changed so that they engine should be good until 5.5/6k and run well for 100k. I did use the infra-red gauge and it pretty much agree with my temp gauge but that was at lower temps when I had stopped. The problem is happening on the motorway after 20+ mins of hard running. I guess I need to start carrying my infra-red gauge with me.

[mycar]

It's good to have a conundrum, don't you think ?

One of the best bits about classic car ownership I've found is it offers you the oppertunity to have at least one conundrum that you can carry round with you at all times. Carburetors are a good source of conundrums, ignition systems too, I've not had the oil temperature conundrum myself but as conundrums go, it's a pretty good one.

The 911 was a great source of puzzlement for me, always something not quite right, always something that needed consideration and although it drove me to near distraction, it meant I always had a handy conundrum that I could pull out of my pocket at any time to juggle with or push round a keyboard with one finger.

The best bit about the conundrums is the longer they hang around, the more you learn about your car. If instead of conundrums you had car learning on a Tuesday you'd never get down to the difference between NGK and Bosch plug heat range nomenclature or the rev to speed ratio of a 1958 A. A conundrum, you see, concentrates the mind.

For what it's worth, I don't think choosing a cooler sparkplug or rejetting for local weather conditions is going to affect the oil temperature as much as you'd like it to. Do you have the grommets on your sparkplug leads and are they nicely fitted into the tinware ?

[neilbardsley]

For what it's worth, I don't think choosing a cooler sparkplug or rejetting for local weather conditions is going to affect the oil temperature as much as you'd like it to. Do you have the grommets on your sparkplug leads and are they nicely fitted into the tinware ?

Funny you should say that because I was going to order some new ignition wires from Paul, for that reason, but he talked me out of it. He said he would try to find some good rubbers and send them with the other bits I had ordered.

I think that I'm chasing a issue that is a non issue as the car really does run very well. I think it now running better than it did when we toured the Black Forest and Andy A (in his 914/6) were surprised, but perhaps not troubled, by the effort he needed to put in to keep up with us going up the mountains.

[mycar]

Don't give up that easily Neil, there's bound to be something wrong somewhere.

What about your oil cooler ? Is it sparkly clean ? Can the cooling air pass through it easily ?

What about one of those alloy oil coolers favoured by the aviation industry ? Practically guaranteed to lower your oil temperature, they do look beautiful even though you never get to see them.

[neilbardsley]

Don't give up that easily Neil, there's bound to be something wrong somewhere.

What about your oil cooler ? Is it sparkly clean ? Can the cooling air pass through it easily ?

What about one of those alloy oil coolers favoured by the aviation industry ? Practically guaranteed to lower your oil temperature, they do look beautiful even though you never get to see them.

I have an alloy oil cooler and I've also cleaned it (well from the outside).

[Nine One One]

Neil,
we have been here before?

viewtopic.php?f=3&t=54240&hilit=oil+temperature


Is it not worth just investing in a decent aftermarket oil temperature gauge and wiring that in with the correct sensor to see if you actually do have an issue, and it is not your old original temperature gauge being a bit temperamental.

You could be searching for something that is not actually an issue at all?
Ian

[neilbardsley]

I did a few bits and pieces on the car over the w/e. I changed the oil by dropping the slump plate. No shinny bits so all was ok. I installed 117 main jets then I took the car out for a hard drive on Sunday morning. I did about 5000rpm, for a while, and saw the temperature raise to 230F (on the gauge) by the time I pulled over at an exit. The temp was down to 190F. I think that stopping on hard shoulder, on our largest motorway, to check engine temp and look at a spark plug isn't such a clever idea. I think that my in car gauge is reading maybe 15/20F to low so when I was pushing the car the temp was close to 250F. The plug looked ok. When I got back I checked the timing and I think that it was too advanced. Maybe 10 degree so I reset to 34 max advance. I took for a quick test drive but ran out of time to test it at high speed again.

[mycar]

I bet the car felt spritely with 44 degrees advance.

I think we might have found the cause of your hot running engine.

34 degrees is about what it should be... 44 degrees will give you holes in your pistons.