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Vtx531

01 Boxster Overheating

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Vacuum fill seemed successful (or so I thought). When I put 15 psi pressure into it to test, the level still decreased slightly but not nearly as much. Not sure how there could be any air in the system. I took it down to 25.5” and it was holding steady.

 

I drove for a few miles, temp seemed pretty steady at 180 degrees and I thought the issue was fixed, but as I pulled back into my driveway, temp began to rise (slightly) to just above 180. I popped the trunk and could hear what sounded like boiling/gurgling coming from the cap area but it didnt flow over and no steam.

 

I am using distilled water until I get this figured out. Could that be having any effect?

 

Weird thing is now the heater seems to not work at all. Before the vacuum fill, it got warm but not hot.

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4 minutes ago, Vtx531 said:

Vacuum fill seemed successful (or so I thought). When I put 15 psi pressure into it to test, the level still decreased slightly but not nearly as much. Not sure how there could be any air in the system. I took it down to 25.5” and it was holding steady.

 

I drove for a few miles, temp seemed pretty steady at 180 degrees and I thought the issue was fixed, but as I pulled back into my driveway, temp began to rise (slightly) to just above 180. I popped the trunk and could hear what sounded like boiling/gurgling coming from the cap area but it didnt flow over and no steam.

 

I am using distilled water until I get this figured out. Could that be having any effect?

 

Weird thing is now the heater seems to not work at all. Before the vacuum fill, it got warm but not hot.

 

Distilled water will not change anything.

 

If you don't have heat, you still have air in the system.

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Maybe there was something wrong in my procedure, here is what I did:

 

1. Remove two large hoses, two small hoses (heater core?), drain plug (nothing came out the drain plug at the end).

 

2. Reconnect all hoses and drain plug.

 

3. Vacuum system down to 25.5”. Let it sit for 5 mins, verified no drop(rise?) in vacuum pressure.

 

4. Allow the water to be sucked in from a 5 gallon bucket

 

Something I am missing??

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3 minutes ago, Vtx531 said:

Maybe there was something wrong in my procedure, here is what I did:

 

1. Remove two large hoses, two small hoses (heater core?), drain plug (nothing came out the drain plug at the end).

 

2. Reconnect all hoses and drain plug.

 

3. Vacuum system down to 25.5”. Let it sit for 5 mins, verified no drop(rise?) in vacuum pressure.

 

4. Allow the water to be sucked in from a 5 gallon bucket

 

Something I am missing??

 

Sounds correct, but obviously if you have no heat from a heater that has full flow all the time, there has to be air in the system, or the doors on the HVAC system are not moving correctly.

 

Pull the cover off on the passenger's side next to the battery, start the car and let it warm up, you should be able to feel both heater lines and see if they get hot.

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I took it for a short drive again- 

 

engine was overheating

 

steam coming out from radiator cap

 

the heat started working intermittently

 

I guess I could try the exact same procedure that I did again but how can I expect anything to change if I don’t do anything different?

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Something 'organic" is wrong here, so let's start with the basic elements of the system:

 

You said you pulled the thermostat and tested it, correct?

 

Do you have the paper work from the water pump install?  Can you see the water pump and verify that it is new?  Is it possible to contact the shop that did the work and find out why they replaced the pump and if the original and replacement pump had a metal or composite impeller?

 

People have a tendency to replace the composite impeller pumps in these cars with aftermarket metal impeller pumps because they are cheaper and people think they are better, which is a big problem.  The clearance between the back of the impeller and the engine case is only a couple thousandth's of an inch in order to get proper coolant flow, and Porsche used composite impellers specifically because as the pumps age, the shaft begins to wobble and the impeller hits the engine case.  If the impeller is composite, the impeller breaks up and fails; if the impeller is metal however, it begins machining away the engine case, creating a much larger gap, and renders any new pump, regardless of impeller type, unable to move the coolant in sufficient volume to keep the engine cool.  Unfortunately, there is no coming back from this a the engine would have to come out and apart to spray weld up the are and then be machined to the correct tolerance's, which is too expensive to be realistic.

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Yes, pulled thermostat and tested good. I have the paperwork from the water pump. It says 42579 which comes up at Gates brand when I do a google search. The photo shows metal impeller but people are “complaining” in the reviews that it is plastic, so who knows... hopefully composite?

 

I drained and vacuum filled the system again. Same result. No heat. I also “flushed” the radiator hoses and heater hoses while they were off with a garden hose and there seemed to be no obstuctions.

 

Water pump and thermostat were replaced because of previous owner overheating.

 

Attached is a photo of the bucket that I filled and how much water it sucked in with the vacuum.

 

New radiator cap should be here in a couple days but I don’t think that would affect the issue with no heat.

26291E85-AA8B-49DE-B01B-F5E4A7B7C4E2.jpeg

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36 minutes ago, Vtx531 said:

Yes, pulled thermostat and tested good. I have the paperwork from the water pump. It says 42579 which comes up at Gates brand when I do a google search. The photo shows metal impeller but people are “complaining” in the reviews that it is plastic, so who knows... hopefully composite?

 

I drained and vacuum filled the system again. Same result. No heat. I also “flushed” the radiator hoses and heater hoses while they were off with a garden hose and there seemed to be no obstuctions.

 

Water pump and thermostat were replaced because of previous owner overheating.

 

Attached is a photo of the bucket that I filled and how much water it sucked in with the vacuum.

 

New radiator cap should be here in a couple days but I don’t think that would affect the issue with no heat.

26291E85-AA8B-49DE-B01B-F5E4A7B7C4E2.jpeg

 

I believe the Gates pump has a metal impeller:

 

spacer.png

I am concerned that the pump was replaced because of overheating, not because the pump had failed or was making noise.  The question is why was it overheating?  At this juncture, if the car was in my shop, I would pull the water pump and look at both the impeller and the wall of the engine case.  If the case is tore up, you are chasing your tail trying to get the system to work.  As for the reviews of the pump, some "complain" the impeller is composite, others complain it is metal, so it sounds like they could go either way.  In any case, we ONLY use the factory water pumps, which are all composite impellers, and work well, unlike several aftermarket brands we have looked at.  Unfortunately, many aftermarket bits for Porsches are really junk; water pumps, surge tanks, and AOS units are great examples of what not to buy.  We have seen several fail right out of the box.  Yes, they are a few bucks cheaper, but after some people have gone through two or three units in quick succession, that few bucks looks like a really bad deal...…..

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Yes, the pump was replaced because of overheating in May 2019 (also thermostat) Appears it was driven 600 miles and taken to another shop complaining of overheating in July 2019.

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2 minutes ago, Vtx531 said:

Yes, the pump was replaced because of overheating in May 2019 (also thermostat) Appears it was driven 600 miles and taken to another shop complaining of overheating in July 2019.

 

You need to look behind the water pump at the engine case wall.

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Although I didn’t get a chance to check the water pump yet, I was able to perform a block test and happy to report it did not turn green/yellow and the plunger sort of stayed squeezed after squeezing it = success (as far as I can tell - first experience). I put the tester up to the tailpipe as a control and it did turn greenish yellow.

 

Also, I did a coolant pressure test with the engine idling and the psi did not increase, no needle vibrations. Really hoping it is just the water pump and not head gasket/block/head problems.

 

I did not do the block test with the engine hot because I don’t want to overheat anything if there is no coolant flowing from bad waterpump.

 

Do you know where the coolant temp sensor is located? I purchased Bentley manual and 101 Projects book but I couldn’t find the answer to that.

 

Learning a lot. Hopefully I will be able to get this figured out.

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As for the Gates water pump impeller being metal or plastic...

 

I found reviews prior to May 2017 saying it is metal and after Jul 2018 saying it is plastic.

 

Mine was installed in May 2018 so it will definitely be a surprise.

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I ran the block test once more. The bleeder was closed the first time. I thought maybe the combustion gas (if any) was possibly leaking into an air pocket or heater core and thought maybe I should test it again with the bleeder open. It passed again.

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21 minutes ago, Vtx531 said:

As for the Gates water pump impeller being metal or plastic...

 

I found reviews prior to May 2017 saying it is metal and after Jul 2018 saying it is plastic.

 

Mine was installed in May 2018 so it will definitely be a surprise.

 

I called two wholesalers that handle Gates and aske them to look, one said metal, the other composite.  I think the Gates is a 50/50 proposition.

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16 minutes ago, Vtx531 said:

I ran the block test once more. The bleeder was closed the first time. I thought maybe the combustion gas (if any) was possibly leaking into an air pocket or heater core and thought maybe I should test it again with the bleeder open. It passed again.

 

Checking the coolant for combustion by products was a good idea, you have removed another possibility.  Now, about that water pump...…...

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Sometimes it is the simplest things.  Glad you got it sorted, now go get a factory pump.........

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Looking at getting a Pierburg pump - thoughts? Supposed to be same as factory?

 

Also, I ordered a new radiator cap because the old one was original and I ordered an adapter to test the caps - Stant 12017 combined with free pressure tester loaner from Autozone.

 

Results:

Old cap released pressure at 12psi and bled down to 7 psi.

New cap released pressure at 19psi and bled down to 17 psi.

 

The shop that the car was brought to prior tested the old cap and said it was “Good-fair”

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As I mentioned earlier, we only use the factory pump.

 

Your old cap sounds beat, the new cap is about right.

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Got a FREE new Gates pump under warranty. Tried to install it and ripped the cardboard gasket, ****. Nobody local sells  water pump gaskets for this car. Nearest dealership is one hour away so I got a new Porsche metal gasket.

 

Went to install the new Gates pump and it seems like the impeller is binding. There is resistance when I turn the pulley and a blockiness to it at certain positions around the clock. Definitely rubbing/contact. I didn’t have the screws tightened down all the way (didnt want to ruin the new gasket) but even so, this seems not right. Confirm?

 

You said you looked at many after market brands that didn’t work well - did that include Pierburg and did you have troubles with Pierburg? I don’t have to worry about call backs or warranty work and cost of labor because I am not a shop and it is my own vehicle but I do need the **** part to fit.

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10 hours ago, Vtx531 said:

Got a FREE new Gates pump under warranty. Tried to install it and ripped the cardboard gasket, ****. Nobody local sells  water pump gaskets for this car. Nearest dealership is one hour away so I got a new Porsche metal gasket.

 

Went to install the new Gates pump and it seems like the impeller is binding. There is resistance when I turn the pulley and a blockiness to it at certain positions around the clock. Definitely rubbing/contact. I didn’t have the screws tightened down all the way (didnt want to ruin the new gasket) but even so, this seems not right. Confirm?

 

You said you looked at many after market brands that didn’t work well - did that include Pierburg and did you have troubles with Pierburg? I don’t have to worry about call backs or warranty work and cost of labor because I am not a shop and it is my own vehicle but I do need the **** part to fit.

 

Just get the factory unit and be done with it.  Piersburg is supposed to be a supplier to Porsche, but the units I have seen in the aftermarket do no look the same. 

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I put in a Pierburg and it is working great on initial test drive. I have nothing to compare it to except the Gates pump.

 

Gates pump is complete garbage!!! The impeller bearing is mounted off center which as causing the binding. On top of that, the impeller was out of round. On top of that (!) the impeller was mounted too high on the bearing shaft. So it rubbed on the tips at first. I filed them down. Then it rubbed on the top edges when the screws were tightened down. Completely unusable piece of garbage! I don’t even know how they can get by selling it. No wonder the brand new gates only lasted 600 miles before it shredded.

 

Also, the impeller is totally different material. Cheap molded plastic on the gates and the Pierburg has some type of composite material that seems almost metallic.

 

Pierburg had a couple pieces of slag (not sure what to call it) that was from the casting. It didn’t look like that great of a casting job. I chiseled off the little bit that was on the inside where the water flows. There were a couple blemishes on the gasket surface too that I sanded down with 600 grit just to be safe.

 

Maybe they are seconds that don’t meet Porsche quality requirements. Said made in Italy and had a 996106101 part number.

 

Thank you so much for all your help and I will be back so you can say “I told you so” if this pump fails me!

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1 hour ago, Vtx531 said:

I put in a Pierburg and it is working great on initial test drive. I have nothing to compare it to except the Gates pump.

 

Gates pump is complete garbage!!! The impeller bearing is mounted off center which as causing the binding. On top of that, the impeller was out of round. On top of that (!) the impeller was mounted too high on the bearing shaft. So it rubbed on the tips at first. I filed them down. Then it rubbed on the top edges when the screws were tightened down. Completely unusable piece of garbage! I don’t even know how they can get by selling it. No wonder the brand new gates only lasted 600 miles before it shredded.

 

Also, the impeller is totally different material. Cheap molded plastic on the gates and the Pierburg has some type of composite material that seems almost metallic.

 

Pierburg had a couple pieces of slag (not sure what to call it) that was from the casting. It didn’t look like that great of a casting job. I chiseled off the little bit that was on the inside where the water flows. There were a couple blemishes on the gasket surface too that I sanded down with 600 grit just to be safe.

 

Maybe they are seconds that don’t meet Porsche quality requirements. Said made in Italy and had a 996106101 part number.

 

Thank you so much for all your help and I will be back so you can say “I told you so” if this pump fails me!

 

I sincerely hope that day never comes.  But you have shown why those of us that fix these things for a living regularly tell people to stop trying to cheap out with aftermarket components; your Gates pump is a poster child for why we say what we do, and why we depend upon factory parts.

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A little late for me to be asking now but I will ask anyways - Do you put locktite on the water pump bolts? I noticed the bolts had a blue residue on them. I did not use locktite.

Edited by Vtx531

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