Hey guys. This morning in DC, i started my car and made my way to work. I noticed that since i cold air was blowing through the vents with the heater on HOT it still gave me no heat even when the temp gauge was in the middle or climbing to the middle. I immediately thought that the vaccuum system controlling the heater core valve went nuts but sure as heck, the car temp still climbed all the way to the red WITH NO HEAT. this happened to me long ago with my M3 because usually ,thermostats fail open to allow coolant to flow ALL the time, which would prevent the car from getting warm "failsafe method" but in this case, just like the m3, the car overheated and continued to overheat. Luckily i made it to a parking lot before more damage occured. Just a little steam as coming from the engine bay when i popped the hood and its full of coolant as of 6 weeks ago. What do i check first? Thermostat? Where and how can i locate the thermostat since i have no diagrams or manual? Can you guys help me. The engine didnt burn steam nor did it run funny so i doubt the headgasket was blown. thanks guys/ gals in advance.

-Tony

 

ALSO, where is the Thermostat located?

 

The engine forum.

Since your title clearly has the word engine in it.

Moved

 

it's been a while since i looked at a 300 engine, but just follow your upper rad. hose to where it meets the engine. the thermostat will be in that housing.

 

**UPDATE**

I got home after leaving the office early so i could work on the car. I realized when going to my park spot that there was a puddle of coolant /water on the parking spot about half the size of the car. I never noticed this when i left of course because i backpark and leave forward everyday. Strange scenario though. I filled the Radiator and noticed that my engine stayed nice and cool for 15 minutes even reving to 3-4 k at times. No smoke out the exhaust as the car has always burned very cleanly. I was even able to get heat in the car, of course due to the fact that hot coolant was now flowing through the heater core. BUT weird thing was that, when i opened up my radiator cap to top it off and burp it, a small amount of foamy fluid was coming out from the top of the radiator at the FIller Spout. YES the radiator had been empty for somereason and was not leaking. The radiator hoses are not cut and are not leaking and my radiator was almost empty for some reason which caused my car to overheat. The foaming........well im an oldschool guy and have never seen that before. Water pumps in older classic cars have huge impellers capable of flowing large amounts of water at low RPMS whereas the newer highly advanced cars require a small - medium sized pump to flow at high RPMs and low too. What is this foam? there is no Oil in the fluid as i have drained it so i dont think the HG is blown or leaking (could be wrong) I have great power from the car and always give her oilchanges.

1. FOAM???

2. Coolant spot under the car?

Have any of you guys experienced this or that in no particular order?

thanks

 

car has been idling for over 30 minutes now with no issues. No water is leaking from the car...........any ideas.

 

rad cap might be bad... allowing pressure to build up and then push out under the cap into the overflow, which then overflows onto the ground.

never heard of foam either. i'd flush taht whole system and refill it with and then monitor it closely.

 

thanks 19. I will try that. the foaming is strange. It idles great and is driving fine too. I will go get that rad cap like you mentioned. Thanks man. ill keep it posted till tomorrow.

 

Ok well here i am again looking for an answer once again.......It seems as though after waiting and leaving the car off for a few hours, i came outside and sure as heck, there was a small puddle under the car. It doesnt leak when the car is on and HOT but instead somehow comes out when the car is cooling down. Now ANOTHER thing is that i noticed since i added water to the car and the car is idling FULLY WARMED UP, that i can easily put my hand on the radiator and its barely warm, the cylinder head is nice and toasty as usual but the radiator and even the cap is cold. Would this matter if its 30 degrees outside because generally i know rad caps and radiators get blistering hot. Ami i wrong or does it sound like a bad thermostat? thanks in advance.

 

I'm a 100% certain its a leak a the water pump. The water gets hotter and expands right after you turn off the car. I've seen this happen to cars before.
The water pump is old, and so is the gasket

 

Luke, Not to question the integrity of your statement, but why would the water get hotter after i turn the car off? The metals in the car expand with heat YES but in the cold they contract and hence would make less clearances. Nonetheless i value your help but can you be more specific as to what you just said. Thanks

 

based on your newest info, i concur with LUke, i'ts the water pump. the coolant is leaking out of the weep hole.
it's gettign hotter when you turn off the engine because it wasn't circulating very well with the enigne on, and when you turn it off, all that heat from the head and block goes right into the water in the head and block which isn't moving anymore.

 

Interesting. Very interesting. I noticed this morning that i had absolutely NO fluids on the ground. I dont think i should complain but it does leave me a bit more confused than before. I will take your guys word for it and try the water pump. Strangely there are no leaks though. I am so lost. i will keep you guys posted. thanks.

-Tony

 

you could always pressure test the system. the leak will show up then.

 

Just got back from the parts store and got an OEM replacement RaD cap. So far there is no difference in the amount of coolant in the system. I degreased the entire engine (minus belts and alternator) with heavy duty brake cleaner (the flammable kind in the green can since it has the most solvent of any, and soaked all that oil and coolant residue off in the parking lot of the store. Drove around for about 30 minutes, pushing the car really hard. (i had also put the RAD cap on the rad at the parts store too) I drove and the temp gauge never moved a smidge over the halfway point. Came home and noticed that unlike last night, the radiator was nice and toasty and the rad cap was hot like it should be. The top of the engine was hot too, just like it should be. i dont remember how hot it should be but it was a definately hot cylinder head. highest i ever take the rpm is around 4.5k so ive never wanted to hurt that motor anyways. I am going to wait and see while it cools down but there was definately no problem while driving. bought a thermostat while i was at it too. I should let you know in about an hour or 2 if theres a leak. thanks again.