Getting Hot

[brian bramble]

[B]Now my engine oil temp is getting High[B]

Along with the sputtering that Ive been trying to "Italian Tune up" out for 10 or 12, 20-40 minute drives.. Now after 30 mins the oil temp is getting higher than I ever remember her getting.

As far as I can tell there has never been a factory cooler. She's a 1975 911s that Ive had for 35 plus years. When I purchased her back in 1988. There was a lines going up along the rocker panels , all that were no longer hooked uo. iShe sat for 15 years after an engine fire and now I've finally got her TO SOME DEGREE running and looking acceptable. Now I'm ready to get busy on all of the little bugs and gremlins. I would say the sputtering at low rpms with small backfires on the exhaust side , are the most bothersome.. But now the hot oil temp gauge is my biggest concern.

please advise

Brian from Cincinnati.

[rwest]

What is hot? I would be fine with around 210F on a warm day.

A lean running engine can cause it to run hot as well as the wrong timing.

[thejobrien]

What is the temp it is getting up to?

[brian bramble]

Thanks for the response . It's getting to the 250 all the way to 270 before I bring her back.. The last thing I need is internal stuff.

Prior to engine compartment fire , I drove her more that season than any other . Absolutely flawless the way she ran.. I never saw the temp get that high. I've got 35 plus years invested in this car, Im not gonna quit until she's running like a sewing machine again. 35 years later , I have a bit more disposable income nowadays , that I don't have to tell my wife (of 31 years) about. It's sentimental now.

[rwest]

Ouch! That is way too hot.

I would suggest a complete going over of all the systems, make your your ignition is in good shape and also the CIS. I would figure that you have multiple vacuum leaks. You might want to do a complete refresh of all the CIS seals, hoses, injector sleeves, o rings etc then adjust your air fuel ratios and timing.

[EC900]

Congratulations on your return to the garage.
Since it ran well before the fire…
During the rebuilding what parts changed out and to what extent the damage that would have contributed to the malfunction.
Could be a missing vacuum hose or leak somewhere, hence a combo of bad timing, idle and mixture trying to compensate.
If so then that’s where the focus should begin backtracking.

During the storage period it’s common that maybe a rodent built a nest under the engine shroud impeding air flow.

The hard lines under the passenger side could be for a trombone cooler or rubber hoses being from AC

[blucille]

I’d look for nesting material or whatever behind the fan on the cooling fins of the cylinders. In addition to all of the above, engine timing and fueling issues can drive oil temps up.

[Ian Comerford]

Did you say that the oil lines along the rocker panels are no longer fitted? If so I would consider re-instating as they provide useful cooling for these cars

[Winter]

Originally Posted by Ian Comerford

Did you say that the oil lines along the rocker panels are no longer fitted? If so I would consider re-instating as they provide useful cooling for these cars

I think you have gotten a lot of great advice. Definitely check for a mouse house, review all the CIS work you have done.

And I have to 2nd Ian - I was looking for an SC with a later engine, but “bought the seller” on my ‘76. There had been A LOT of work done on mitigating heat for the 2.7: 12 blade fan, Elephant lines to a Turbotrol front cooler. I’d address everything mentioned by the experts in this thread and then add a front mount cooler and lines. My 2,7 rocks all day long at 210, even driving across western Kansas for hours after I purchased it in Columbia, MO.

[brian bramble]

Thanks to all of you. The lines running a long the passenger side rocker are abandoned a/c lines . I have very little interest in ever going back with AC. I checked for vacume leaks with starting fluid ,,and I did find one.. I replaced that one , now the idle change with the starting fluid is nearly non existent.

[brighton911]

I second the guys that have said look for signs of a rodent nest. Then check the oil thermostat as a next step.

[brian bramble]

Wouldn't driving her around make a mouse house pretty unlikely? From what I can see there is no house but I cant really see back in there .. Should I dig deeper ? Maybe a Micro Cam? Im pretty much stuck right now as I don't want to keep trying to 'drive' the sputtering bugs out , with her getting so hot. As far as a faulty gauge goes,, I'm pretty sure that we're running hot..

[blucille]

You can shine a light in between the fan blades and see what’s up. Rodents love the spot. Especially back towards the firewall. Cyl 3&6. You can likely snap some photos of what’s in there if you can get the camera to focus back there.

[EC900]

The rodent nest blockage is one of the simplest possibilities that has to be eliminated before going on to other culprits. Mechanically the only other way to increase engine heat fast is no fan belt, assuming yours isn’t loose and the correct pulley and shims are used, including that the engine tins and side covers are in place too.

Also - Get an infrared thermometer gun and Temp check at the sender unit after you take another drive and see if gauge is accurate. Pull the gauge and clean the terminals and the Ground.

Borescope inspection camera will help and always a good tool just to have anyway.
It will make looking under the fan shroud easy, but also you can remove the small tin shroud cover plate on the right side. Looking thru the blades, you’ll only see one side and quarter way in.
Shine a flashlight and lower your cellphone camera and take a video until you’re satisfied the area is clear.
Or a blast of air will rustle up any debris enough (if any) in there to chase out any matter with cover off.
Usually there will be other evidence of rodent habitation (old or new) like acorns, shells, twigs, leaves, cotton fiber, etc on your engine tin.

The coming and going of a rodent would leave a messy trail so it becomes obvious they nested under the shroud. Operating the engine could have blown most of the old debris to the back and out of sight. Again if you’ve opened the engine compartment before any reason, it’s somewhat obvious but if you don’t think about it or ever thought a critter would take up residence there, likely it’s unnoticeable.
I live in mouse chipmunk retreat zone and make the inspections frequently and keep set traps year around.

There was a used 911 engine for sale on BaT auction site that had a perfect example of a rodent nest protruding from the fan, unfortunately I can’t find the old listing.

For what it’s worth, I have a 2.7L and No Aux Oil trombone or rad style cooler, and on the hottest, sunniest summer afternoon 85°-95°F , I’ve seen gauge at 220-240s° F maybe more but from idling too long at a freight train crossing (I pulled u-turn to go back) or heavy traffic or long lights.
Once moving along, the engine cooled back down to 190°-200° range for summer that’s expected, winter 20°-40° F I’ll see 180-190° range.
Just as important, Oil type and oil level along vehicle movement keeps temps down.

[brighton911]

Brian, you are right, the heat would make it unlivable for Mickey. That said, he can build a nest in a single night (with the engine cool) so get in there with a borescope and have a look.

[brian bramble]

4 hours later... I put the rear pan and side shields back on. I haven't put the heat hoses back on yet because I'm not quite sure where they go. It takes me a minute for this all to sink in..My thought was , since that rear plate wasn't on that it would create more air circulation. As soon as I figure out where to put those heat lines , I'll give her a go again.. Thanks hopefully the overheat is fixed and I can go back to figuring out the sputtering and exhaust back-coughing.

[rwest]

You need to have the engine tins and heat hoses in place for cooling, otherwise the fan might be working less than optimal or blowing air out rather than over the cooling fins on the cylinders.

I also firmly believe the poor running of your engine could be a lean or timing issue and contributing to the excess heat.

Have you made sure your firing order and timing are correct?

[brian bramble]

thanks rwest.

The car runs so well on the high end ,that I can't imagine there being something that drastic. The sputtering is almost like she's running "fat" as the coughing and sputtering are mainly after a stop or a return to acceleration. As if not burning fuel in the cylinder but past that in the exhaust.

I truly appreciate all of the input! I'm sure I'll get her back to where she was.