Still overheating!!!
- Thread starter m5runner
- Start date
Well, it's for real now......this car clearly has a problem. I was in traffic friday and it shot all the way up to the 3/4 mark and was heading to overheating. I turned the heat on to full blast and it went back to the center marks. The car doesn't leak antifreeze so I am basically stunned at this point in time. Maybe someone can really shed some light. I am at the point where I am afraid to drive the friggin car
Overheating issue
I didn't see a list of what you've changed but I'll give you some suggestions. BEFORE you change anything out, take a thermometer (avail at parts stores or some shops) while car is running and warm, remove rad cap and take the ACTUAL temp. I say this because factory temp gauges & sensors develope "hot spots" and will give a different reading if the hot spot exists. Compare your reading to the thermostat temp (I presume you've replaced that) 9 out of 10 times it's just a minor glitch at the guage/sensor. Build up on the sensor or anywhere in the coolant passage ways can influence a minor reading change. A pinhole drip in a head gasket can make the guage move also. If it's a pinhole you wouldn't see steam in the exhaust. Below is possibilities:
Thermostat - these are not mega science part & are not all perfectly calibrated.
Waterpump -(you mentioned you changed)
Radiator cap - the seals wear
Head gasket seepage - you might want to try a product called Bars Leaks. The factory puts the equivalant of 4 bottles in EVERY vehicle during assembly. It's a super sealer & coolant system coating. (I had an E34 that they forgot to tighten top hose clamp and I drove to first Oil Service before noticing and it never leaked a drop)
A good COMPLETE cooling system flush
Check your fan cluth and aux fan.
Bottom line - if it's just a hair over mid mark, I'ld just keep an eye on it. It sounds like you're on a quest but you might be stressing over nothing. Hope these help
I didn't see a list of what you've changed but I'll give you some suggestions. BEFORE you change anything out, take a thermometer (avail at parts stores or some shops) while car is running and warm, remove rad cap and take the ACTUAL temp. I say this because factory temp gauges & sensors develope "hot spots" and will give a different reading if the hot spot exists. Compare your reading to the thermostat temp (I presume you've replaced that) 9 out of 10 times it's just a minor glitch at the guage/sensor. Build up on the sensor or anywhere in the coolant passage ways can influence a minor reading change. A pinhole drip in a head gasket can make the guage move also. If it's a pinhole you wouldn't see steam in the exhaust. Below is possibilities:
Thermostat - these are not mega science part & are not all perfectly calibrated.
Waterpump -(you mentioned you changed)
Radiator cap - the seals wear
Head gasket seepage - you might want to try a product called Bars Leaks. The factory puts the equivalant of 4 bottles in EVERY vehicle during assembly. It's a super sealer & coolant system coating. (I had an E34 that they forgot to tighten top hose clamp and I drove to first Oil Service before noticing and it never leaked a drop)
A good COMPLETE cooling system flush
Check your fan cluth and aux fan.
Bottom line - if it's just a hair over mid mark, I'ld just keep an eye on it. It sounds like you're on a quest but you might be stressing over nothing. Hope these help
WARNING - This could result in a SEVERE scalding injury! Removing the radiator cap while the car is hot and running to measure thermostat temp means the system will be under pressure and at 180 to 215 degrees.
The proper way to do this is to remove the cap when COLD and run the engine until it warms up. NEVER remove the radiator cap when the engine is at temperature. You will at a minimum leak a lot of coolant and could be seriously burned.
A better test is to remove the thermostat, and heat it in a pan of water on the stove, measuring the temperature.
I think you mentioned a while ago you had replaced some parts. Was the thermostat replaced, and are you sure it is the right one, and it is not installed backwards?
The proper way to do this is to remove the cap when COLD and run the engine until it warms up. NEVER remove the radiator cap when the engine is at temperature. You will at a minimum leak a lot of coolant and could be seriously burned.
A better test is to remove the thermostat, and heat it in a pan of water on the stove, measuring the temperature.
I think you mentioned a while ago you had replaced some parts. Was the thermostat replaced, and are you sure it is the right one, and it is not installed backwards?
Yes it's the right one and it has been replaced multiple times. At first it was a hair over the mid marker but when I was in traffic on friday waiting for the cops to catch that freak of nature that shot up Atlanta it started overheating rapidly. I turned the heat on to max blast and it bought it back down to the middle within a minute. Every major cooling component was replaced
That's what my buddy/mechanic told me. He said he has some spot weld crap that he can pour in it and fix it. Not sure if I want to go that route but who am I to question him? He has been fixing bmw's about the same time I have on the planet. I'll try and get it done some time this week because summer is coming and it gets really really warm in Ga
Check your fan clutch. It seems that the coolant system is all under control, but I'm betting that your fan clutch is the culprit. Run the car until it's hot -- until it's at that 3/4 mark. Turn it off. See if it's hard to spin the fan. It's mechanical, so it can't run unless your engine is, so you won't cut your fingers off.
I'd bet on it being the fan clutch, especially with the problem showing up while sitting still in traffic.
I'd bet on it being the fan clutch, especially with the problem showing up while sitting still in traffic.
does your electric cooling fan turn on? Let it get to operating temperature and see if the electric fan works.
I think i read all your posts and didn't see a result as to wether or not it works.
Does the fan turn on when your A/C turns on? Does it overheat with the A/C on?
If you had a head gasket leak, you would not be able to cool the car back off with your heater i highly doubt, and you would be able to see bubbling in your expansion tank while it started to warm up/overheat.
I think i read all your posts and didn't see a result as to wether or not it works.
Does the fan turn on when your A/C turns on? Does it overheat with the A/C on?
If you had a head gasket leak, you would not be able to cool the car back off with your heater i highly doubt, and you would be able to see bubbling in your expansion tank while it started to warm up/overheat.
You could also double check other suspects:
- bad NEW thermostat
- foreign object in the system that is blocking flow
Before you tear it down for a head gasket, you should answer the question I asked before: are you loosing coolant but can't find any leaks? Also, Does the coolant look oily? Do you see any water in the oil? Does the exhaust look steamy even after the car warms up, or smell like coolant? Is your oil pressure dropping off? Slow loss of oil pressure can indicate that the oil filter is becoming water logged and not allowing oil to flow.
- bad NEW thermostat
- foreign object in the system that is blocking flow
Before you tear it down for a head gasket, you should answer the question I asked before: are you loosing coolant but can't find any leaks? Also, Does the coolant look oily? Do you see any water in the oil? Does the exhaust look steamy even after the car warms up, or smell like coolant? Is your oil pressure dropping off? Slow loss of oil pressure can indicate that the oil filter is becoming water logged and not allowing oil to flow.
to answer your questions: I am losing coolant but can't find any leaks. Coolant doesn't look oily at all. It's nice and green except for these little black things I see in it but not much or significan't to worry about. Exhaust looks fine, no steam or anything. Oil pressure I really don't know how to check or know how to tell if there is a difference but nothing seems irregular other than the coolant loss
now you are losing coolant??
you said you weren't earlier. Are you losing it quickly? When you overheat, coolant will overflow out of your expansion tank relief valve. You will have to figure out if you are losing coolant all the time or only while overheating.
Did you check your auxilary fan yet? Did you try the air conditioner overheat yet? (my last post?)
you said you weren't earlier. Are you losing it quickly? When you overheat, coolant will overflow out of your expansion tank relief valve. You will have to figure out if you are losing coolant all the time or only while overheating.
Did you check your auxilary fan yet? Did you try the air conditioner overheat yet? (my last post?)
ok, let me clarify the "losing coolant" part before i continue. the car IS losing coolant because ever so often i have to top off the radiator with some coolant. I look under the car and there are no leaks and no signs of it inside the engine bay. i haven't checked the aux fan but i don't think it has anything to do with the car losing coolant
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Is yours overheating as well?
the auxiliary fan should come on with the a/c as well as when your main radiator get to a certain temperature. It should come on at an even higher speed if your radiator reaches a certain higher temperature.
If it is not doing so try replacing your radiator temperature switch. Think its around 20 dollars. (or test to see if it is working with a multimeter)
Welcome to the board by the way!
the auxiliary fan should come on with the a/c as well as when your main radiator get to a certain temperature. It should come on at an even higher speed if your radiator reaches a certain higher temperature.
If it is not doing so try replacing your radiator temperature switch. Think its around 20 dollars. (or test to see if it is working with a multimeter)
Welcome to the board by the way!