Boxster 986 Engine Temperature

[ProjectM96]

Hello everyone, The temperature was always a little high on my Boxster between 190 and 195 degrees F. I believe the 986 Boxster engine operating temperature should be 186.5 degrees F in the middle of the gauge. Is it normal for the temperature to be slightly passed the middle on the temperature gauge? I bought the car 8 months ago and since then drove 4000 miles with no problems until last week.

Last week, my 00 2.7L overheated. The temperature warning light went on around 205-210 degrees F(Needle at 3/4 line of temperature gauge). All the coolant leaked out. It happened at the end of a 3 hour drive(160 miles) just minutes from my destination. Filled the coolant/antifreeze tank twice and drove a short distance about 1/2 mile before it over heated again.

Towed it to a mechanic. He could not find any problems with the newly replaced water pump. He said the thermostat was fine. His Guess to the solution was to close the coolant/antifreeze cap tighter to prevent air from getting into the system.

After he tightened the cap, I drove the car for 30 minutes about 15 miles normally driving without pushing the end hard. It seemed to work. The temperature was moving from high to low often reaching 197-200 degrees almost at 3/4 the temp gauge, then cooling down at red lights back to around 190-195. The warning light did not turn on, but I wanted to drive harder to see if the warning light will tell me it is overheating.
Then I tried driving the car very hard revving to the redline for 1 mile, but temperature did not go any higher, which was good news.

But is it normal for the temp needle to be passed the middle on the gauge? Is it normal for the engine to reach about 200 degrees F?

[mcmike27]

Something is causing the temps to shoot up. Are the cooling fans for each rad operating? Can you hear them? They should be kicking on if the temp guage goes where you are describing. Also do you have the new version coolant cap? There might be an air bubble in the system and thats a serious problem. It can cause specific heating to delicate parts of the engine and lead to all kinds of nasty issues. If the WP and T-stat are working and the fans are coming on thats where I would start. Also have the front rads been cleaned out? You'd be AMAZED at the junk that collects in there basically choking the air flow to the rads. If you have an air bubble thats an easy fix that can be done with or without a pressure tester.

Good luck..

m2

[turboflyer]

+1 on the cleaning. I even had mesh covers on the inlets and after 70K the amount mulch that gets through is not good. There also a considerable amount of fins that need to be straightened and rocks picked out. Be sure to pull the A/C condensers from the radiators. There will be another surprise between them. I added aluminum screen to the inlets to keep more crud out. Be careful with the plastic air dams on the condensers as the clips become brittle. You may want to order some plastic fasteners as well. The fender well covers do not need to be completely removed as show in the manual. Hope this helps some. If you need to replace a horn, now is the time.

[ronster]

Originally Posted by ProjectM96

Hello everyone, The temperature was always a little high on my Boxster between 190 and 195 degrees F. I believe the 986 Boxster engine operating temperature should be 186.5 degrees F in the middle of the gauge. Is it normal for the temperature to be slightly passed the middle on the temperature gauge? I bought the car 8 months ago and since then drove 4000 miles with no problems until last week.

Last week, my 00 2.7L overheated. The temperature warning light went on around 205-210 degrees F(Needle at 3/4 line of temperature gauge). All the coolant leaked out. It happened at the end of a 3 hour drive(160 miles) just minutes from my destination. Filled the coolant/antifreeze tank twice and drove a short distance about 1/2 mile before it over heated again.

Towed it to a mechanic. He could not find any problems with the newly replaced water pump. He said the thermostat was fine. His Guess to the solution was to close the coolant/antifreeze cap tighter to prevent air from getting into the system.

After he tightened the cap, I drove the car for 30 minutes about 15 miles normally driving without pushing the end hard. It seemed to work. The temperature was moving from high to low often reaching 197-200 degrees almost at 3/4 the temp gauge, then cooling down at red lights back to around 190-195. The warning light did not turn on, but I wanted to drive harder to see if the warning light will tell me it is overheating.
Then I tried driving the car very hard revving to the redline for 1 mile, but temperature did not go any higher, which was good news.

But is it normal for the temp needle to be passed the middle on the gauge? Is it normal for the engine to reach about 200 degrees F?

My '99 Boxster had 74K miles on it when I bought it and it ran just a hair above 180F deg. for 10K miles. I had the LN ceramic IMS bearing installed and a new RMS and after that the temp went up to as high as 199F deg. It fluctuates between 185-199F deg. but has never gone over 200 mark even on the hottest days and longest drives. Both my fans are working and after the car started running at the hotter temp I had the water pump replaced but not the thermostat. The radiators were blown out but not cleaned with front bumper off. The car seems to run fine at these temps and I can't see anything about the IMS replacement that would cause temp to go up so that must be a coincidence. I've also installed mesh grills over the front inlets to keep out debris.

[nosnow4pc]

I had a simular issue with my 99. I had the LN bearing installed and I replaced a main cooling hose that looked soft. Got the car back ran perfect, the first hot day the car started belching coolant all over the place. I topped it up and decided to replace the coolant cap as it was the same symptoms from a previous cap failure, haven't had an issue since.

This is the 2nd cap in 2 years.

[ProjectM96]

I still have the old cap. I guess I will order a new one just incase and clean the radiators.

Thanks everyone. One last question. Is the IMS failure only known for 96-99 Boxsters, or the 2.7 engines in the 00-03 too? Because from what I see on all forums, only people with 99 and older models report IMS failures and replace them with the 2.5L engines.

[ronster]

Originally Posted by nosnow4pc

I had a simular issue with my 99. I had the LN bearing installed and I replaced a main cooling hose that looked soft. Got the car back ran perfect, the first hot day the car started belching coolant all over the place. I topped it up and decided to replace the coolant cap as it was the same symptoms from a previous cap failure, haven't had an issue since.

This is the 2nd cap in 2 years.

What temp does your '99 run at now? I also had replaced the coolant cap with the upgraded one long before I had the LN bearing installed.

[nosnow4pc]

Usually it runs right on the beginning edge of 8, if I am in stop and go traffic it will go to the middle of the 0 the fan kicks on at the end of 0 and it drops back to the front of the zero. If the engine ever gets warm (to the 0) the temp never goes below mid 8. I hope that makes sense.

Given my experience I believe once coolant vents through the cap the cap has to be cleaned or replaced. I say this because if you look around the tank dried coolant is a crusty red and I have a feeling that causes a poor seal if cap vents. Also make sure the cap is on VERY tight.

The car has 141,000 miles and the water pump was replaced ~128,000.

[mcmike27]

Another great inexpensive upgrade for the non 'S' Boxsters is to install a 'S' oil cooler. It's almost twice the capacity and bolt's right on. All you need is a new set of 'O' rings. I picked one up from a salvage yard in LA and that combined with the L&N 160 t-stat has made a nice difference with respects to cooling. Adding the 3rd front rad would be ideal but we dont track our car only a few AX's during the year. The best easiest thing to do is to stay on top of the debris between the A/C cond and the front rads. When we cleaned ours this spring you could have filled a horse stall with the amount of crap we pulled out from between those units.

[dad911]

You said the water pump was recently replaced. It took me a long time to get all of the air out of the system when I refilled it. Thought I had major problems, every time I went out on the track it spit out coolant and tank was empty.

Fine once we got all the air out.