Engine overheating and oil pressure light



I was driving my fiance to work this morning in my 2003 VW Beetle when the high temperature warning light came on and beeped. A little bit later the oil pressure light came on as well, but only for about 30 seconds and then shut off. We had been driving for about 15 minutes and were on the highway when this happened. There was no steam coming from the engine. We were right by where we needed to be so I pulled off the highway and into the office complex which was right off the highway and checked the coolant and oil levels. I just had the oil changed maybe two weeks ago and the oil level is fine. The coolant level looks perfectly fine as well. I let the car sit for a while and then drove it back the two miles to get home. A few minutes after starting to drive the high temperature light came on again. Still no steam or anything but there was a slight burning smell after I stopped and went up to the front of the car. I’m not driving it until I get it fixed, whatever it is, but I don’t really have much money to do anything until next week. Does anyone have any idea what the problem might be? I’ve only had the car for about five months or so and it has just over 100 k miles. I don’t think there is any kind of leak, because before I got my oil changed two weeks ago I got it changed somewhere else and they didn’t tighten the oil filter enough and it was leaking oil. So I took it to another place to get another oil change so they could fix the problem. I told them about the leak and they said they would check to make sure that it wasn’t something else that was leaking and they didn’t find any problems other than the oil filter. I have never had any issues with the car overheating either. And I don’t know if it’s just me being paranoid, but while I was checking the car out after I got home and it had been sitting for a few hours, I turned the engine on for a second and it seemed to be making a bit more noise than normal. Not really anything out of the ordinary, just regular engine noises, only louder.


Somebody needs to hook up a mechanical oil pressure gauge, as well as take readings of the engine oil and coolant temperature . . . with separate thermometers


An oil circulation problem can cause the engine to overheat, so I’m thinking along the same lines as db4690 above, good idea to at least verify the oil pressure is at spec. If this were my car I’d worry that the oil filter was plugged or defective, so I’d also do a drain and refill, making sure the oil spec meets VW recommendations for your car, and replace the filter with one I’d buy from a VW dealership (an OEM filter), looking inside the old filter for any metallic debris, and sieving the oil that drains out for the same.

It’s possible of course this is just a dashboard light or sensor problem. But until you are certain of that, suggest to do what db4690 recommends, at the minimum, get the engine oil pressure measured using a shop gauge.


I’m afraid it might be more than “just a dashboard light or sensor problem” . . . because OP said the engine was making more noise than normal


Again I’m not a regular fan of oil analysis but this might be a case to do an analysis to see what metals are in the oil or any other contaminants. If you change the oil once again, get at least a 1 liter sample of the oil in the middle of the change to send in.


The OP said the car had a slight burning smell. Were your radiator cooling fans running when the temp light was on. How did you check the coolant level, at a radiator cap or in a coolant reservoir? Warning , do not remove a radiator cap until the car has cooled down to where you can put your habd on the rad.

Also, if your car is running hot, the heat can thin the oil, causing the oil light to come on.


A stuck thermostat could cause this.


How did you check your coolant level? Did you remove the radiator cap and look in the radiator or just check the overflow reservoir? BTW, you should only loosen the radiator cap when the engine is cool. You can get burned by hot coolant if you open the cap while it is hot.


My car apparently doesn’t have a radiator cap, just the coolant reservoir, which is very full. I’m not sure about the fans, I’m going to check them out in the morning when it’s light out.


If it doesn’t have a radiator cap, then you should remove the reservoir cap when it is cold and look inside. The plastic reservoir can get stained to the point that you can’t really see the coolant level with the cap on.

It should be full up to the line on the side, or in some cases, to the parting line where the top and bottom halves meet. That cap is a pressure cap and if it looses the ability to hold pressure, it can cause overheating. It has to be put on very tightly.


I checked it after I let it sit for a few hours. It was pretty hard to see the lines on the side because they placed the windshield wiper reservoir directly in front of the lines, but I took off the cap and looked inside and outside and it looks likes it’s a bit above the max line, where the upper and lower half meet. And I don’t see any leaks. So I don’t think it has to do with coolant levels. I don’t know if the radiator might be gunked up and need a flush? I have no clue when that was last done by the previous owner.


If your coolant is clear, colored but clear, like a piece of colored glass, then I would not flush. If it is cloudy, then it needs to be changed but I still would not flush. If it appears muddy, then flush although be prepared that a flush wont fix the problem. You will need eyes on by a good mechanic to find the issue. Visibility through the internet isn’t very good.


I checked out the coolant and it looks good and clear, a nice clean pink. I’m thinking at this point it might be a stuck thermostat, but I’m getting it towed to a mechanic hopefully today, so we shall see!


I’d have thought an overheating engine would thicken the oil, not thin it. That’s why the oil specs are for example, 10W-30. 10 when the engine is cold, 30 when the engine is hot. What am I missing?


You don’t understand how multi-vis oils work. Look up the viscosity curves.


Oops! That’s what I get for doing my own thinking! You are right, the viscosity of 10W 30 decreases uniformly w/temperature. 10W 30 is lower viscosity at colder temperatures than 30, but pretty much the same as 30 at higher temperatures.



Overheating can cause lubrication failure and lubrication failure can cause overheating. One of oil’s functions is to wash heat from the cylinder walls. And also to prevent heat-causing friction from numerous key bearings and surfaces.

Honestly, this vehicle needs a good hands-on look-see by a competent shop. I’d recommend you get it towed to your favorite mechanic. He’ll probably want to start by evaluating the condition of the coolant, oil, cooling system, oil pressure, and… dare I say it… even a leakdown test of the cylinders.


Yeah, it’s not something that I can figure out at all, so we are taking it to my fiance’s family mechanic that we’ve gone through a few times with this car. And the best thing about him is that since we don’t know what’s wrong this time he won’t charge us a bunch just to figure out what the problem is. I hope it’s not something too bad, as we’ve spent so much money on this car in the five months we’ve had it (burnt out headlight, broken power windows, new front brakes, four new tires, clutch totally crapped out, and still need new struts, rear brakes and something wrong with one of the axels.)I love the car, but I’m honestly thinking that it might be worth it to just trade it in or sell it once I’ve fixed everything and get a newer car that won’t constantly have issues.


Brakes, tires and clutch are wear and tear items

You can’t really count that against the car

Same thing goes for the struts and rear brakes

The car is 13 years old . . . I don’t know what kind of mileage you have, but most cars at that age need several hundred dollars of maintenance/repairs every year

Be aware that there is no such thing as a car which never requires spending money on repairs. But some are more reliable than others. How about Honda/Acura or Toyota/Lexus. Too boring for some, but if reliability is what you’re after . . .


Just over 100,000 miles on a VW so anything is possible.