Boxster S Tiptronic Overheating at DE

[PorscheJack]

I have a 2000 Boxster S with Tiptronic. Two years ago, at 100k miles the motor failed at a Drivers Ed (DE) Event. Likely a cylinder wall "D chunk" failure as there was mixed oil and water, and oil coming out the exhaust. I had the car taken to the local Porsche dealer and installed a Porsche reman motor. The old motor had never overheated.

The new motor has overheated at DE events quite consistently. I have had the engine temp light come on at one event (about 90 deg outside) and have stopped running at 250 degrees at other events. On the road, the temperatures are normal. Needless to say, this is a tough problem for the dealers, as they can't reproduce the problem in the shop. To date we have replaced the thermostat, the coolant bleeder valve (twice as it was leaking), all three radiators, the resisters for the cooling fans and the transmission bypass valve.The last event (late Sept) at 60 deg. outdoor temp, the motor was running at 225. The shop forman at the dealer came to the track and did confirm that the car was running hot (both water and oil) and that the fans (radiator and engine compartment) were operating properly. The dealer has said that he has no other ideas. I requested a replacement motor, but the Porsche rep. reportedly told the dealer that "he has seen Tiptronics overheat at track events" and has said Porsche will do nothing to deal with the problem.

Two questions. Mine never overheated with the original motor.

1. Can any of you confirm that you do track events with a tiptronic and tell me how the temperature reads?

2. The warrantee on the motor runs out next week. Any suggestions on how to deal with Porsche or to escelate the problem?

Comments appreciated.

[wvicary]

Sorry I can't answer your questions but have the coolant pipes been inspected for any restrictions? Perhaps the metal pipe work has been damaged in some way.

[whall]

Radiator inlets clean and clear of debris?

Bill

[mikefocke]

I'm going through a mental list of what is involved in cooling and come up with a water pump you haven't changed and the heat exchanger. Short of measuring the amount of anti-freeze flowing into the radiators I can't think of anything else....unless it is your gauge. Have you used the HVAC controls trick to see what the temps are? My link

[infocusf8]

I track and AX my '99 Tiptronic and never had the temp go up until I had the LN ceramic IMS bearing installed and now the car runs nine degrees hotter consistently on or off the track. My water pump recently went out and I had it and the coolant replaced and thought that would remedy the problem but it didn't. My car has never gone over 200 deg. and stays right around 199 up from the 180 it ran at pre IMS change. Don't know if I should be concerned about the temp increase but 199 doesn't seem that critical to me. Tips weigh more and have their own cooler but I don't know if this has an effect on over all temp or not. You might check the trans cooling system if you haven't all ready. To be honest with you I've asked questions about my tip to dealer mechanics and independent Porsche trained mechanics and their operation seems to be a mystery. At my last DE my instructor was freaking out over the shifting pattern of my tip but I've gotten used to how it shifts so it didn't bother me. Prior to my doing the 90K service on my tip I couldn't get the tip to downshift into first at AX and was forced to deal with the very long build up to power curve in second gear after coming out of tight braking turns. After the service the car easily downshifts into first in those same turns and let's me blow out of the hole with power cutting seconds off my times. This probably doesn't help your case and I will be following this post to see what the cause is just to add to my knowledge base od this mysterious thing called Tiptronic.

[PorscheJack]

Thanks for the comments guys. Some quick responses. The radiators and ducts are clean - the front end as been off the car twice this year, once to replace the radiators and onces to replace the cooling fan resisters. The "old" radiators were quite dirty - it looked like the car had driven into a mouse nest(I still rather wonder if a mouse didn't get in there when the car was in the shop for a week). However, even though the radiators were about half plugged, on the highway in hot weather, the temperature was only up about 1/2 of the digit "0" in 180. So when the radiators work, they seem to have lots of capacity. The Porsche shop forman came out to the track on the last DE and plugged in the Porsche code box and confirmed that both water temp and oil temp were high, so that rules out the temp guage. The oil to water "cooler" is new with the rebuilt motor, so it should be ok. (It looked new in the photos of the new motor). The transmission control valve that regulates transmission was also replaced (at my espense - as is most of the work - I think Porsche covered the thermostat).

The suggestion of checking the oil lines is a good one, but given the number of times that the car has been on the hoist, I would have thought that the shop would have done that.

Any other thoughts, especially on how to approach Porsche, would be welcome.

[mikefocke]

And what would Porsche's response be...you changed a part to a non-Porsche part so go ask them.

Have you asked Charles. Or Jake. With 1k of their bearings out there (and I know they track their own cars) you'd think if it were a bearing or an install problem they would have seen it before. Yea I know it is a TIP but lots of TIPs track at least to the DE level and lots of them have LN bearings by now.

I also wonder if, just because a part is new/replaced, we aren't assuming something that isn't true..that the new/replaced part is good.

Have you tried shooting the entire system just after you come off the track with a heat measuring gun and comparing against another similar car? Maybe that would give you a clue. Those guns run only $30. Maybe, because your system is running hot even on the street you could even get a clue there.

[flameout]

I just bought a 2001 tip boxster (base), It overheated almost immediately, I changed the oil and filter mobil1 0=40w, changed antifreeze and drove it it overheated aboutv20 min, the engine fans and radiator fans came on, coolant leaked out from the cap.It seemed like a classic, water pump failure, or possibly thermostat stuck. Well I got them both out and the pump is still good, and I checked the thermostat in. Hot water and it opens at around 210, any other ideas?

[RFM]

Be sure there are no air bubbles left in the cooling system, best to use an airlift vacuum device as on this topic post # 22 (http://www.renntech.org/forums/topic/32508-radiator-flush/page-2?hl= cooling system fill) it's very hard to get the air out in the conventional way.

[JFP in PA]

RFM is correct; we see a lot of problems with air trapped in these cars after a DIY repair or maintenance on the cooling system. It is often difficult for people to get all the air out of these systems without using a vacuum filling system, particularly the Tip equipped cars, which have a oil to water cooler on the trans that is part of the cooling system loop.

[txhokie4life]

Clean out your radiators, my guess is they are filthy.

m

[JFP in PA]

Clean out your radiators, my guess is they are filthy.

m

Often a contributing factor, but based upon experience, he also has air in the system.