Author Topic: Running hot - cooling system part 2 (Read 3541 times)

RH318is · « **on:** December 16, 2008, 06:47:35 PM »

A while ago I posted a question about my 318is running hot when idling at a stop light. I'd taken it to a shop and they said the thermo, clutch fan, hoses, etc. were fine. No leaks. I do notice after running the car only about 15 minutes there will be water dripping out, looks to be on the left/drivers side of the radiator on the ground.

Today, I noticed when stopped at stop lights (since the outside temp. is cold/only 45 deg.) the air coming out of the heater got cooler, then when driving away from the green light the air from the heater got warm, more like normal. Does this indicate anything specific?

monty23psk · « **Reply #1 on:** December 16, 2008, 09:19:34 PM »

very possible thermostat is bad. You can test it easy but removing it and testing it in a boiling pan of water. At least that is what I would do.

Are you still dripping or temp going up?

roundel318 · « **Reply #2 on:** December 16, 2008, 09:37:15 PM »

The second time my car overheated, it cracked small parts of the radiator.
I had similar issues with loosing fluid at times after it had heated up.
The radiator was original and the plastic ends don't hold up well to overheating, anyone with a E36 water pump that had plastic impeller blades can give you additional input.
New radiator and stat. Spendy but fixed the problem

The cool air at stop and warm when moving indicates a variety of things, namely pressure loss, low level of coolant, air in lines, and of course a bad stat

RH318is · « **Reply #3 on:** December 16, 2008, 11:01:44 PM »

I'm putting about 24-40oz. of water a day now. I've driven it a couple times for 40 minutes (each way) on the freeway. When I arrive some fluid is on the ground when I start to come back and then when I hit some stop lights when I get back the temp. starts rising. If it's a long light I start getting nervous because the gauge goes up/above 3/4.

I'm mostly driving it just 15/20 minute or short trips and putting water almost daily. Could something just be blocking a water way that a coolant system would clear out or does it sound like something more/more expensive?

RH318is · « **Reply #4 on:** December 16, 2008, 11:02:17 PM »

Sorry, double post.

roundel318 · « **Reply #5 on:** December 16, 2008, 11:17:47 PM »

If you really want to find it, your mechanic will have a florescent dye to add into the coolant to find where it is leaking from.
If the coolant isn't getting into the oil, it must be going somewhere

Probably the ground, suggesting you have a leak....

RH318is · « **Reply #6 on:** December 16, 2008, 11:25:43 PM »

A leak in the radiator?

txleadfoot · « **Reply #7 on:** December 17, 2008, 08:00:47 AM »

I had this issue when the heater hoses at the firewall were reversed.

Quote from: RH318is;62964

Today, I noticed when stopped at stop lights (since the outside temp. is cold/only 45 deg.) the air coming out of the heater got cooler, then when driving away from the green light the air from the heater got warm, more like normal. Does this indicate anything specific?

monty23psk · « **Reply #8 on:** December 17, 2008, 09:05:24 AM »

Well first thing is to find source of leak, which will introduce air into the system and thats why your temp is going up. If the leak is in the front by the radiator it would be the radiator, hoses to and from the radiator or the cap. Look for coolant streaks. You might have to clean that area good before to have a good look.

RH318is · « **Reply #9 on:** December 20, 2008, 11:22:05 AM »

Thanks for your help guys. Guess it probably is a leak, and since the shop said the hoses were fine and they didn't find any leaks (in their defense I didn't let them keep the car very long) it probably is the radiator. The cap is also new.

Would the air in the system also account for it running/starting rougher than normal? Hopefully I'll have time to look at it over the holidays. For now it's short trips.

roundel318 · « **Reply #10 on:** December 20, 2008, 12:47:57 PM »

Hopefully you didn't overheat it too bad to damage the head, Starting and running rougher than normal isn't what you want to hear.....

RH318is · « **Reply #11 on:** December 20, 2008, 02:47:42 PM »

Thanks been my concern since the temp/cooling system started acting up a couple months ago. I'm pretty sure it hasn't been over heated, unless you can over heat it without the guage running into the red/and the radiator steaming over.

It started rougher since the shop worked on it. I think they pressure tested the cooling system and I thought maybe some stuff got mixed up or something. But it does slightly remind me of how it ran when I first got it 8 years ago and 3 months later the engine did a "hydrolic freeze". A different shop said there was a hair crack and I had the head replaced.

roundel318 · « **Reply #12 on:** December 20, 2008, 05:51:18 PM »

If you havent' buried the needle, you should be good to go in the head warpage dept.
Save your temp guage isn't on crack?

I have buried the needle three times due to overheating and have 267k on the clock with no known head warpage (engine runs tight with no real issues).....

RH318is · « **Reply #13 on:** December 20, 2008, 08:08:27 PM »

Ah, thanks for the info on your head. I think the head is still ok. I've decided get a new car, but not for another couple months, so I'll add water and just take short trips until I sell it.

Thanks again.