Engine overheating/radiator problem

[jgood808]

Ok I have read every post on overheating and I am still at a loss. Here are my symptoms. Car overheated and when I raised the hood, I had steam coming from my t-stat. Ok, easy fix, I replaced it, went to burp it and the temp gauge went straight to 12oclock and stayed, however there is steam coming from in between the radiator and the overflow/fill bottle. It won't burp it just gives me steam all the time, if I take the bleed screw out it blows steam, when I close it, it has steam coming from between them. WTF is going on, is my radiator done or is something loose. Also, I noticed that my aux fan only comes on when the a/c is on. Please help before I bring it to a shop.

Here is a pic of where the steam comes from.

Thanks,
Jeff

[cooljess76]

All that rust near the hose and between the expansion tank and radiator would indicate a cracked radiator. That's a common place for radiators to leak, you should replace the radiator.

[jgood808]

Yeah, I think that is best, how indepth is it for DIY? And also is it better to get a new one or used(like from a junkyard). Trying to save some dough here!

[jgood808]

Also, you know of some good parts stores down in San Diego? I know a few, but I get the feeling you know some good secret spots!

[cooljess76]

Originally Posted by jgood808

Yeah, I think that is best, how indepth is it for DIY? And also is it better to get a new one or used(like from a junkyard). Trying to save some dough here!

I wouldn't advise buying any used cooling system parts. It's so important not to overheat these engines and it's just too much of a risk to take by installing used parts that are critical to keeping things cool. I bought a Behr radiator a couple of years ago and the quality was the same if not better than OEM. I never heard of this brand before, but the price seems pretty reasonable:
http://cgi.ebay.com/ebaymotors/SPECT...Q5fAccessories

For a little more, you could upgrade to an aluminum racing radiator, but you'd have to figure out a way to mount a remote expansion tank and run custom hoses.

[jgood808]

got it thanks for the advise. Now, trying not to bother you too much, but was out messing with it, and noticed that the lower radiator hose is cool vice same temp as the upper one, I just replaced the t-stat, could this be my water pump also? Or as I read in another post on here that there is a bleeder hole that has to be at 12oclock, I am going to pull it an check.

[cooljess76]

Originally Posted by jgood808

Also, you know of some good parts stores down in San Diego? I know a few, but I get the feeling you know some good secret spots!

Unfortunately I wasn't into BMW's yet when I lived in San Diego. There is a place in Costa Mesa that I recommend called Mesa Performance. Those guys are really knowledgeable and they only carry quality parts. I'm sure there's other places, hopefully someone else can chime in. Hit up member "Southpaw", he lives down in San dog

[cooljess76]

Originally Posted by jgood808

got it thanks for the advise. Now, trying not to bother you too much, but was out messing with it, and noticed that the lower radiator hose is cool vice same temp as the upper one, I just replaced the t-stat, could this be my water pump also? Or as I read in another post on here that there is a bleeder hole that has to be at 12oclock, I am going to pull it an check.

No worries man, Yeah it's possible the water pump may be bad. Usually you'll hear them when they start to go bad though. It's recommended to replace ALL of the cooling system parts including the plastic coolant fittings that are notorious for breaking, especially if it's unkown when/if they were replaced before. As for the bleeder hole, are you referring to the one on the thermostat itself? I think I remember reading something about that. What year is your car? '95's had M42 engines that used an aluminum thermostat housing with a removeable thermostat. '96 and newer models had M44 engines which used a plastic thermostat housing which had the thermostat integrated into it. The water pump should only install one way. There is a bleeder on top of the radiator next to the fill cap and if you don't already know, bleeding the system is a very critical step whenever messing with the cooling system. http://www.318ti.org/forum/showpost....02&postcount=3

[jgood808]

Its a 98 with the plastic housing. When I try to bleed it, it spurts and spurts but and then it starts to steam, which is now making me think that the pump is bad and is not cycling water through the system. I havent went to 50/50 coolant as of yet because I have already went through 5 bottles and it costs to much, so I am just using distilled water until I finish trouble shooting.

[cooljess76]

It really shouldn't steam if you're bleeding it right. The engine shouldn't be reaching operating temperatures while the radiator cap and bleed screw is off. Read the instructions carefully in the link I posted above.

[jgood808]

It gets to 12oclock in about 8 - 10 minutes of idling but no hot air or steady stream from the bleed hole. I think it is the water pump also...small project coming up me thinks. Oh well it will be all good in the end and I will have no cooling issues after that(praying)!

[cooljess76]

Distilled water is fine for now, but don't run it that way for too long. You want atleast some coolant in there as it works as an anti-corrosive and lubricant. Coolant also increases the boiling point of the water. You may also consider a product made by Redline called Water Wetter. It reduces surface tension and helps air bubbles escape as well as increases the boiling point so I'm told.

[cooljess76]

Originally Posted by jgood808

It gets to 12oclock in about 8 - 10 minutes of idling but no hot air or steady stream from the bleed hole. I think it is the water pump also...small project coming up me thinks. Oh well it will be all good in the end and I will have no cooling issues after that(praying)!

The whole bleeding process should take no more than 2-3 minutes each time. The reason you're not seeing a steady stream coming from the bleed hole is probably because you're not filling the expansion tank high enough. Don't worry about overfilling the expansion tank. It levels off as soon as you drive the car. Keep pouring coolant in until it looks like it's going to overflow out of the fill hole. You'll start to notice coolant coming out of the bleed hole. If you're worried about wasting coolant, place a bucket under the car to catch the coolant.

Also, if you spill coolant on the street or driveway, be sure to hose it down thouroughly. Not only will it leave a nasty rust stain, dogs happen to like it because it tastes sweet, but it's also poisonous.

[jgood808]

Ok....update! replaced thermostat, upper and lower hoses, waterpump, and radiator...not that hard about 2 hours...tried every step to the t on bleeding the system...i must be mentally retarded because all i get is a lot of spurting, i keep filling, thermo opens sucks down coolant, spurt spurt....then steam....solid steam, temp stays at 12oclock until i close it up and then starts getting hot, no heat in car....done this about say 10 time already....i am totally at a loss right now...any ideas

jeff

[pdxmotorhead]

Put the car on ramps and get the front about a foot in the air. (Supposedly helps)

Some time I want to find a M44 and compare it to my 1995 M42 because mine never gives me a bit of trouble, the water just pours out of the bleeder. I keep wondering if its a routing issue with the hoses to the heater that aggravates the bleeding issues..

I always use watter wetter in my rigs, I also use the BMW coolant only. <shrug>

Good Luck

Dave