08 boxster overheating - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Vza · 10-21-2021, 10:01 PM

So I purchased a 2008 boxster w 42000 miles from a scrapyard. Took for its maiden voyage on the highway and the engine overheated. I added some coolant before leaving cause the low coolant light was blinking. About 40mins in the temp gauge jumped and was pinned to the right with no gradual increase. I also smelled electrical burning. Warning light blinked engine too hot. Immediately shut down...cooled off got it home. The 'eng.too hot 'came on again as I pulled in the garage. Hope I didn't do ant damage to the engine. Today it cranked right over....let in run half hr and the temp gauge didn't move. This issue is the 1st to fix on this long restoration. I'm thinking the thermostat isn't opening and probably needs to be replaced along with the temp sensor. Or...faulty temp sensor isn't allowing the thermostat to open....no signal. Any help would be great. V

husker boxster · 10-22-2021, 04:34 AM

The electricl burning smell is not good, but let's start with 2 basic questions:

Did you use European antifreeze? Mixing regular antifreeze with European blend will cause a serious problem - your mixure becomes a sludge that obviously doesn't flow very well thru the system. I'm not going to get into which brand of Euro antifreeze you should use, as long as you used it vs regular you'll be OK.

Did you 'burp' the system when you added antifreeze or just dump a bunch in and drive? If you didn't burp the system, you could have an air bubble in the system that could be caught in a cyl head. This will cause an overheating issue as a hot spot forms where the bubble is and that can lead to serious / expensive consequences. Don't be driving around for long periods with an overheating issue. Search on 'burp' to find the exact procedure.

If these 2 questions were answered correctly, then you can check the thermostat. Just wanted to start basic and move up the diagnosis chain.

If you're having electrical issues, it would be wise to toss a fire extinguisher in the car. You don't need a car-b-q situation. And hopefully you're not venturing too far from home on your test drives. Last yr when I was bringing my 928 back to life, I just drove around the neighborhood until she proved to be reliable enough to venture further out.

Trust is earned.

Vza · 10-23-2021, 08:44 AM

I just added some coolant before the drive, didn't burp. Don't know what kind of coolant was in it before. I think I will try and resolve the gauge issue first cause now the gauge is dead....didn't move after the car idled for half an hour. So maybe replace temp sensor see if that was the electrical burn I was smelling. Then add coolant and burp the system. If it still over heats check the thermostat. I'm thinking thermostat only cause the car was abandoned and probably not been driven in years.

Stl-986 · 10-23-2021, 04:53 PM

thermostat wont have anything to do with an electrical smell. It isn't electric, it is just a thermostat.

pilot4fn · 10-23-2021, 08:39 PM

What color was the coolant you added?

Vza · 10-23-2021, 09:15 PM

I know its not electrical...i just think I have multiple issues, a dead temp gauge and over heating, just going to do the temp sensor, water pump and thermostat and maybe the center radiator upgrade while I'm at it. I added zerex G40 coolant...pink.