New Guy

[Samuraiace]

Hey everyone, figure the typical new guy thread is needed. I've been browsing around this site for a while now and decided it's about time I get in on things. I have a 1987 Porsche 944 N/A few regular mods, have had her for almost two years.
I'm into doing work myself if I can, and I learn fast. I've been all over the car but have gotten to the point were I could use some advise from you guys. Anyways Thanks for having me.

[FrenchToast]

What advice do you need?

Where are you located?

Welcome!

Be safe, have a good evening!

Cheers

[Dave Colangelo]

Welcome,
Post some pics of the car, as well as your location.

This is the place for information, do you have a recent problem?

Regards
Dave

[Samuraiace]

Thanks

I'm in the US, Central Vermont

The problem I've been having is with cooling, or well the lack there of.
My temp gauge is going from low end temp to high end third white line.
I've done a head-gasket, coolant flush, temp sensor, thermo fan switch, and Redline.
I had a euro garage take a look at her and they tested the temp both by heat gun and a line into the coolant and said she wasn't hot. So I'm figuring that it's grounding to the gauge???

Like I said I'm, not sure if thats it or not or how to go about checking, so any input is helpfull at this point.

[Dave Colangelo]

The first thing I would do is clean all the grounding points on the car. If you have the haynes or shop manual they are all labeled in there. Just pull the bolts and sand the tabs to clean copper. Grounds on this car can be a real electrical nuisance. You should change the thermostat as well its a 20$ piece can can some times be a real issue. If that does not fix it I would consider a new water pump and if you have not done it the timing belt while you are in there. Regardless of what the euro shop says I would get advise on what proper temp of that block should be from this forum then measure it. My shop manual says the thermostat should open between 178 and 185 Fahrenheit so proper operating temp must be some where around there. Hope this helps.

Regards
Dave

[ernie9944]

^^ Good advices,welcome ___Samuraiace___ also check your expansion tank cap.Pics of grounds location on your 944, also schema of water circulation.For most of your maintenance this will be your friendly garage Clark's Garage Home Page once on site enter "Garage Shop Manual".Click on T then scroll down.

[Samuraiace]

I forgot to add that when I did the thermostat that when I went to pull the old one there wasn't a thermostat. The previous owner had either forgot (yeah ...sure) or removed it, I'm guessing when they were having head-gasket problems, i.e heat problems. I put a Beck Arnley thermostat in and it was rated at 195, the fans were kicking on at 190. The gauge is reading at the upper range mark when the coolant temp is at 190.

[Samuraiace]

ernie 9944 thanks alot for the diagram that helps alot

[hangar21]

Welcome, I had a similar problem with over heating (north Texas) and after trying new coolant and thermostat, I finally replaced the water pump. The new pump had "more and larger" vanes than the old one, now sure why? Anyway, all is now cool! I also purchased a new radiator, waiting for weekend before I tackle that project. Hope this helps.
All the best,
Terry

[Samuraiace]

Hangar21 that was my last course of action to try, but being the most expensive of the options I figured I'd exhaust all my others before shelling out the cash. But I agree that sounds like the most likely gremlin to attack next, thanks. What type of water pump did you end up going with?

[Samuraiace]

Looking over my receipts It looks like my water pump was replaced about 53,000 or 54,000 miles ago. Do they wear out in about that time?

[Samuraiace]

I'm still kinda lost if anyone has anymore ideas?

[mytrplseven]

If I'm not mistaken there's thermostats in the 180 degree range (which I installed in my '87 NA) and car's been running in proper range. Make sure the temp switch for the fans match the range of the thermostat. If the timing belt is a bit loose, the water pump will slip and of course hotter temperatures. A collapsed radiator hose will also ensure hotter temps. Water pumps should be replaced with every other set of timing belts which should be replaced around 40K miles or 5 years whichever comes first.

[dangerous]

Waterpumps don't usually wear out and make the car run hot. Usually, it is the bearing in the water pump that wears out and allows coolant to leak. It is possible for a bearing to seize up and stop coolant circulation (and cause the timing belt wear), but less common.

Unless I missed it, your list of work didn't mention radiator. Radiators are often the cause of overheating problems because people run tap water which leaves mineral deposits. Flow efficiency is reduced. I would pull that radiator out and take it to a radiator shop and have it flow tested. These radiators can be rodded but the key factor is whether or not the shop can get the plastic tanks off without breaking the aluminum tabs. Sometimes they bend okay, sometimes they break off. If they break, you just have to replace the radiator, but it is worth a try. I've had 944 radiators successfully rebuilt before and they were back to flowing at 100% for as little as $40 (but that was a 6-7 years ago).

Some people think removing a thermostat will improve the cooling problem because they assume that more flow is better. If coolant flows too quickly, it doesn't transfer enough heat in the radiator. Flow rate is balanced with air flow and surface area. The flow must be controlled within a range. This is the job of the thermostat. One tip that I have found useful is to drill a 1/8" dia hole in the flange of the thermostat and when it is installed, keep the hole at the 12 o-clock position. This helps the bleeding air out of the system.

Don't focus on the water pump unless you are leaking coolant or it is seized. Look at fans if you're hot when not moving. if you're hot while driving, you should look at coolant level & bleeding out air. Once you know your coolant level is good, it's about efficiency which goes to the radiator.

Good luck

[Cocacolakidd]

One other thing to check on before more expensive repairs are undertaken is to check on the Temperature sensor it's self. If the Euro Shop that checked your motor temp and said it was OK the temperature sensor for the VDO gauge could be faulty.

There are two Temperature Sensors on the top of the motor, under the J-Boot. One is for the DME Temp Sensor (Tells what temperature the motor is for fuel balance in DME operation). The second Temperature Sensor if for the gauge in the dash pod. If that sensor is faulty/incorrect the motor may be fine, but the gauge reads wrong.

[Samuraiace]

Dangerous ,I had a coolant flush done, I don't think I would have a problem with the radiator after that. However could it be that I did run my car on one of the coldest nights of the season? My car had some really weird issues that night, frigid negative numbers for weather with extended running that night. Could my waterpump have frozen before I ran it and killed it from running in such bad conditions? How do you check for a dead waterpump anyway?

Cocacolakidd, I had the temp sensor under the jboot on top of the block done.

[dangerous]

Remove your timing belt covers (or just the top cover) and start the engine. You can see where the timing belt turns the water pump pully. If that pully isn't turning, and is shredding the back side of your timing belt, then the WP is seized.

I cannot think of any issues from driving in cold weather. I drove my car for many years in Germany and it was plenty cold.

Flushing your cooling system is a good, however it will not solve the mineral buildup in a radiator. We're talking about a buildup of mineral deposits, like calcium. A flush is not going to do anything about these deposits, it literlly has to be scraped away which is why they rod a radiator instead of just flushing them. The flush will move fluid and soft contamination only. Think of it like the dentist removing tarter with the metal hook. You can rinse all day but, it 's more of a preventive measure rather than a reactive one. Now if flush your system with a hose, you're going to have tap water in your system...which is not ideal. The water in some areas is more mineral free than others so I'm not saying it's something to lose sleep about, it's best to use distilled water only.

Cooling systems are fairly simple. You have coolant circulation, air flow, and a point of thermal transfer (the radiator), pressure.

If you're engine is hot while you sittting in traffic, but cool while you are moving, then your problem is related to the fans. The fans are activated by the thermo swicth (temp sensor) just under the upper radiator hose on the driver's side tank. There's a fan relay in the fuse box (the big one in the back). There's wiring and the fans themselves.

If you're hot all of the time, then you need to determine if you have coolant circulation. Enough coolant or air trapped in the system? Circulation (water pump not owrking)? Once you know you have coolant and no air, you ensure your pump is moving the water.

The cooling system is pressurized and this increases the boiling point of the coolant. If your system cannot maintain pressure, it will not function properly. Leaks prevent the system from achieving adaquate pressue. a filler cap may fail to release excessive pressure.

Contamination is a common problem on these cars due to the oil cooler seals. When (and I say "when" rather than "if" because it tends to be something that occurs sooner or later) your oil cooler seal fails, coolant and oil mix and you usually end up with the milkshake in your coolant system. It can be a real PIA getting that gunk out.

Last but certainly not least is the radiator. Unless it is new, it is a potential suspect and the older it is, the higher the probablilty that is may be restricted to some extent. It is easy to remove and cheap or free to have it tested. A new or freshly serviced radiator will make a world of difference.