Another overheating question

[drifter22840]

Ok, i have an '87 924s and blew my upper radiator hose. I first thought was that it was my thermostat, then i seemed to forgot my first thought and replaced the hose and did a flush/fill on my cooling system. now i am over heating. I think the water pump is still working because I'm not leaking coolant and i seem to still have pressure. I still get heat in the car and i know if you pull the thermostat out the heat wont work. Since i have had the car (more then a year now) i have not had a working temperature guage (mistake i made when i bought it). So now i remember my first though and go to replace the thermostat; looking at the diagrams provided by pelican, Do i have to take out the water pump to replace the thermostat or just remove the lower radiator hose?

Another question is how can i trace my dashboard temperature guage back to the motor and see if it was disconnected when i bought the car?


Thanks

[Gary2397]

I am new to this forum. But, I would like to offer some advices. I think you know as well as I do, the 924S has the same engine that 944s had.
You need the following parts to solve that overheating problems.

1. Lower temperature thermostat
2. Thermal fan switch that activates fan 25 degree F
3. Use only GM approved DEX- COOl Anti-Freeze coolant (red color)
4. Use only Mobile One Synthetic motor oil 10W-30 or 10W-40
Loosen the Air release screw enough when pouring the coolant into the
radiator unti it leaks out from the Air release screw. Then do not forget to tight
it back on.
AS for replacing the thermostat, you don't need to take out the water pump.
Just remove the lower radiator hos
you need a snap ring plier. Check the water temperature connector, or replace a new one. It has only one wire connector attach to it.

I will provide more advices in the near future if you don't mind.

[HondaDustR]

you need a snap ring plier.

...and gorilla hands...and lots of patience (I mean LOTS!).

It's got to go exactly into the groove all the way around the thermostat and is very tricky.

I've heard on the forums here that the lower temp thermostat is not a good idea, since it will not allow the engine to get hot enough to burn off the condensation that collects in the crankcase on cooldown. Maybe it is useful for fixing something that's overheating, but it seems like that would just be compensating for a deeper problem.

[2Tight]

The combination of the lower temp fan switch and low temp thermostat will drive you crazy. The fans will cycle on/off constantly and needlessly. Find out why you are overheating first, you probably have air in the system. Bleed your system well, then do it again, and again. The lower temp thermostat will do nothing to make your car run cooler; it just opens earlier. Once your car is warmed up the thermostat usually stays open until you turn the car off. Fix your temp gauge if it hasn't worked in a year.

Unless you live in Baghdad there is no reason your car should overheat with OE parts that are working correctly.

[drifter22840]

Ill try first to bleed the system again (it was the first time Ive ever done work on a cooling system) I prolly have air in it. As for the water temp connector where is it located?

I used in my car Prestone mix with any color coolant, and Valvolene high mileage oil synthetic blend 20W-50

[Gary2397]

Sorry guys I did not mean to step overboard here. I guess it depends where you live and how the climate is. I used to live down the California. My high mileage 1983 Porsche 944 had overheating issue all the time. It's been 12 years now after replacing these two parts I never have any heating problem . How can it drive you crazy it only cycle when it needs to that is only 70 degree F' compare to the OE.

Sometimes one needs to abandon certain OE parts to improve efficiency and performance.
Afte you bleed the system and correct the temp guage and see where is the needle rests.
May be you need only lower temp thermo fan switch. Prestone also makes DEX-COOL(Phosphate Free) anti-freeze.

Why using 20W-50 grade oil not unless you have a oil burning motor. I think using this thick of oil will make engine run hotter and give you bad gas mileage.

[BeerBurner]

Originally Posted by drifter22840

Ill try first to bleed the system again (it was the first time Ive ever done work on a cooling system) I prolly have air in it.

For whatever it's worth, it took me several attempts before I finally got all of the air out of my system.

BB.

[John_AZ]

FWIW-Do a search on "Connecting rod failure".
Gary2397-If you use a synthetic 10-30 in these engines you will be prone oil leaks but more important is that the engine was built for the 20-50 oil to keep the number 2 rod bearing happy and not self distruct.
Some solutions to high temp. Get new radiator, use Redline water wetter, OK to use Gary2397 lower thermostat and fan relay info and of course, get air out.
IMO

John_AZ
1988 924S
1987 924S

Running cool in AZ on 20-50

[HondaDustR]

Originally Posted by Gary2397

May be you need only lower temp thermo fan switch. Prestone also makes DEX-COOL(Phosphate Free) anti-freeze.

.

Does anyone know if Dex-Cool still clogs radiators and dissolves aluminum, plastic, and head gaskets like it did back when GM had some problems with it?

http://www.consumeraffairs.com/news04/2006/08/gm_dexcool.html

I've been using it since I got my car and haven't had any probs with it, but... Have they modified the formula since then to actually not destroy your engine. I would assume so, since it's still on the store shelves.

[2Tight]

Originally Posted by HondaDustR

Does anyone know if Dex-Cool still clogs radiators and dissolves aluminum, plastic, and head gaskets like it did back when GM had some problems with it?

http://www.consumeraffairs.com/news04/2006/08/gm_dexcool.html

I've been using it since I got my car and haven't had any probs with it, but... Have they modified the formula since then to actually not destroy your engine. I would assume so, since it's still on the store shelves.

It never was the DexCool itself that was the problem. It was the GM claim it didn't have to be changed until 150K. Mix that claim with the poor design of the head and intake gaskets on their entire V6 line and it spells doom. The gaskets would leak causing the coolant to vent out the corrosion inhibitors and become more acidic over time. Anyone that thinks any coolant can go more than 3 years in normal use is delusional. I've used Dex-Cool for over 8 years with no issues on all aluminum, alum/CI, and all CI. I do change it out like any coolant every 2-3 years though depending on the mileage. The newer phosphate/silica free blend is pretty good.

[Gary2397]

John AZ,

I could not remember when I first started using synthetic motor oil in my car. I know it is over five years now. Back then, I didn't know much. Now, whenever I do oil change I mix oil additive call Lucas Oil Stabilizer with 10W-30 due to the car high mileage 225K.

Will I experiencing bad gas mileage if I use 20W-50? In OR, the weather is not that hot like AZ.

[John_AZ]

Now that you mentioned an oil additive and I do not have the background, I will go to my peers: Ultimate Motor Oil Thread or Why we hate CJ4/SM oils.

John_AZ

[myskyon]

Originally Posted by John_AZ

FWIW-Do a search on "Connecting rod failure".
Gary2397-If you use a synthetic 10-30 in these engines you will be prone oil leaks but more important is that the engine was built for the 20-50 oil to keep the number 2 rod bearing happy and not self distruct.
Some solutions to high temp. Get new radiator, use Redline water wetter, OK to use Gary2397 lower thermostat and fan relay info and of course, get air out.
IMO

John_AZ
1988 924S
1987 924S

Running cool in AZ on 20-50

please do not say the engine was "built for 20w50" and being prone to oil leaks is another false statement. as oil leaks are bad seals and have nothing to due with the oil you use. there are a bunch of thread on this board about oil and what weights to use look them up and read through them. I am always recommending what the manual says : "use Porsche approved oil only". That statement rules out 20w50. i know you will want to argue with me but I am done.
Now back on topic....
when you bleed the cooling system drive the car up on a set of ramps and turn the heater on full hot. and start the car with the bleeder OPEN. and wait till there is no more bubbles coming out of the bleeder. one that is done drive the car for a few days checking the cooling system level and toping it off until all of the air is removed. or you could pressurize the system and just force out all the air. another thing you may want to check is that your fan relay is working and turning on your fans. if the fans do not come on then the car will overheat. I have a low temp thermo switch in my car and I love it. when i park my car the fan will cycle on and off to keep the car cool. with turbo parts the car gets hot when turned off. a low temp thermostat IMHO is not necessary unless you are in a very hot environment like the southern states and you use a/c all the time. in the PNW it is not needed.
well good luck with the car and use the search on here. there is a ton of information.

[myskyon]

Originally Posted by Gary2397

Will I experiencing bad gas mileage if I use 20W-50? In OR, the weather is not that hot like AZ.

yes you will. i went from 19mpg using 20w50 to 25mpg using Porsche approved 0w40. I also learned how to drive with out my foot in it all the time. but the oil made a huge difference. also you will notice startups are much better better oil pressure readings. you wont have to wait 30minutes for your oil to get warm. and a bunch of other good things. some will say 20w50 is best for the car but they don't have hard proof other than saying "i have been running it for 100k miles with no problems." though what they don't see is the ware on the internal parts. Porsche has a very very strict and rigorous test to approve oils. but just read all the arguments and make the decision for yourself.

[nize]

1) if the car was working fine before (ie; not overheating) and
2) if the only thing you did was replace a radiator hose and flush/fill the system and
3) the car is now overheating

the most likely reason is because you haven't 'vented' all of the air out of the coolant system. this is a very common mistake. more details here;

http://www.clarks-garage.com/shop-manual/cool-02.htm

[John_AZ]

Myskyon. I have read your argument on the 951 board: Oil viscosity question- rebuilt engine, and your arguments are convincing. I did use the wrong wording "built for 20-50 oil". I did look at my owners oil guide and various weights are provided.
Gary2397. Your choice of oil is listed as well.
Porsche has reviewed the improved oils and has revised the recommendations.
http://www.wrightune.co.uk/downloads/approved_oils.pdf.

Thanks for the info.

John_AZ

[myskyon]

John_AZ i have on my home computer a link to the 06 recommendations I will post it up for you. As every year it is updated. this is just more information for you. thank you, for seeing what was worded incorectly. I have sevral copys of the owners manual and it is somewhat confusing when looking for the correct oil to use in these cars. As it is very easy to over look the one statment in there :

Use only engine oils which meet the specifications designated by PORSCHE.

As you have just stated you have seen the Porsche approved oils list. and can see that it appies to our cars.

ontopic....

is there any update to the over heating?

[nize]

Originally Posted by John_AZ

Myskyon. I have read your argument on the 951 board: Oil viscosity question- rebuilt engine, and your arguments are convincing. I did use the wrong wording "built for 20-50 oil". I did look at my owners oil guide and various weights are provided.
Gary2397. Your choice of oil is listed as well.
Porsche has reviewed the improved oils and has revised the recommendations.
http://www.wrightune.co.uk/downloads/approved_oils.pdf.

Thanks for the info.

John_AZ

good link john, thanks. did anyone else notice that there is NO 50 weight oil on the entire porsche approval list?