overheating

[codeesdad]

I have a overheating issue on a 381ti i have replaced the radiator, waterpump, thermostat and have bled it to death still overheating and the heater is blowing cold air any help out there

[Manolito]

I would pull the top radiator hose off. Start the car and watch it warm up. After about two minutes, the thermostat should open and water should start flowing out of that hose. If it does not, remove thermostat and try again. Work your way back down to the water pump and back to the lower radiator hose until you find the obstruction to flow.

Has anyone put radiator stop leak in this car? That stuff can do an amazing job of bridging water passages in the head. Also, has anyone replaced the head gasket? Wrong head gasket or wrong orientation can block flow.

[coolbear1]

Usually if the car is overheating,and the heater wiill not blow hot air, there is air in the system.

How do you go about purging it?

[Jeron]

In addition to the questions above...

How long does it take to overheat and under what circumstances?

[codeesdad]

a bit of history:
1. got the car in Dallas drove it home and drove it work and back for about 6 weeks appx 30 miles a day. Car has about 60K miles on it
2. Driving home one afternoon the bleed plug in the top of radiator blew out check eng and temp guage went in the red
3. Stopped and cooled it off, filled it with coolant and water drove it home aprox 6 miles with out a overheat issue.
4. Replaced the radiator it was broke. I put it back together and filled it and bled the system according to the instructions, i drove it less than 2 miles and it overheated
5. so i replaced all the Possible causes, water pump, thermostat, filled with coolant and water bled it like 5 times. there is good water flow with the radiator cap off the tank level goes down when the fan comes on. with the cap on it overheats in about 3-5 minutes cant go more than 2 miles.

6. I have purged it by opening the bleed valve and running the motor until it purges out the bleed valve. I have done this with the radiator cap on and off.

I tried turning the key to the acc position and turning the heat on with the fan on high.

There is no water in the oil so i ruled out head gasket.

Unknown if there has been any stop leak used in it.

[Jeron]

When it overheats does the needle ever fluctuate between normal and hot?
Do you "ever" get hot air from the heater?
You are bleeding with the heater on, correct?
From a cold start it will overheat in 2 minutes even if you are driving at 40mph?

[codeesdad]

the temp gage usually goes to half way and then jumps to 3/4 and i shut it down before it goes to the red

i a bleeding it with the heater on

the heater dosent blow hot air even when overheating

[coolbear1]

Overheating comes up allot, and getting the air out is not simple sometimes.
But take a look at this post and see if it helps, can't hurt to try one more time.325i Runs hot

[Jeron]

If it jumps quickly to 3/4 it is likely air in the system. When it jumps to 3/4, try putting it in N and reving the engine to 4k, if it drops then definitely air in the system.

[ausaf]

My Car has also facing this problem wat i do?




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[Wayne 962]

It does sound like air in the system, as the temperature jumps are usually caused by air bubbles / gaps. Let the engine run and leave the bleed screw open and pour coolant in until it flows out of the bleed screw for a short while. Then attach the bleed screw, and let it cool down a bit, and repeat. See if that helps...

-Wayne

[machintek]

I am in the same boat. 96 318ti. fan quit, coolant blew out. refilled. Cannot get coolant to circulate. Car is overheating. Heater on high.
Removed the thermostat. Still overheating. Pulled the water pump. It is OK. Removed radiator hoses. Radiator and hoses blow through freely. So does the engine. Thus no obstructions.
Tried every which way possible to bleed the system except high revs.
Still the radiator is cold. Coolant starts to boil in engine after 5 minutes and shoot coolant out of radiator.
Calling it quits for today!

George

83 911SC
96 318ti
82 928, 95 Xj6
2000 S4

[coolbear1]

BMW's can be so hard to purge sometimes. It is really rediculous.
It recently came up in a post that the expansion tank could be allot of the problem, but I don't think it was ever resolved.
Mine has always been a pain. I always seem to get the air out, but never the first time after a good overheating.

The key is to get just enough coolant into it before it overheats, even if you have to shut down the motor and come back to it several times.
Sometimes it will pull the coolant into it as it cools.
Then start it up and repeat. Just stop it each time before it boils and repeat, maybe it will give you a break.

If it boils you start over because of the loss of the liquid turning to steam and the expansion of the steam pushing out the liquid so fast.

Hope this helps, and I feel your frustration, been there.

[machintek]

Thanks coolbear1.
I Googled this issue and it seems to be VERY common. Intend to find highest point in system (possibly heater core) and either loosen a fitting, do something, pressurize the system using a shop vac in blow mode, until air is out, and try again. I already drilled 1/16 inch holes st the top of the thermostat plates to assist air purge. A few high revs may help too. I will advise how it goes. These cars also use a very high temp thermostat.

George

96 318ti
83 911SC cab euro wide body (US MARSHALL AUCTION drug dealers car)
2000 S4
95 XJ6, 82 928

[socalxtreme]

hello everyone, im new to the forum and i have a question about the cooling system on my 328i.. i recently changed the head gasket and the entire cooling system, everything turned out great, the car purrs like a kitten, the question is : what should the temp guage read normally after warm up? i get a 12 o'clock needle, is this correct?

[Jeron]

Yes, the needle should hit 12 o'clock within a few minutes and then never move.

[socalxtreme]

thanks jeron

[Duke4AZ]

Originally Posted by coolbear1

BMW's can be so hard to purge sometimes. It is really rediculous.

I generally do quite a bit of research before I start to perform a project that I have not done before or is slightly out of my comfort zone. Working on my '98 e36 328i sedan is no different. I recently replaced the head and pan gaskets, the water pump and the timing chain cover. In the process I replaced everything in the coolant system north of the firewall except the radiator and expansion tank. This last weekend, I replaced both of those. Short story long here, because of this post, and the write up in the 101 Projects book I was given a heads-up on how messy this bleed process can be. I hate uncontrolled fluids. Leaks drive me insane. So, I was not interested in getting coolant all over my recently cleaned engine compartment just to bleed air from the coolant system. Here is what I did.

First, I found a small funnel. See pic inserted. The bottom of the funnel as to be small enough to fit into the bleed hole, but not so small that coolant will flow around the outside of the funnel tube and leak all over your engine compartment. I raided my kitchen and found one that worked quite nicely. The funnel acted like a reservoir to capture the overflow from the expansion tank, and allowed the fluid that was forced out of the tank to flow back in.



One other little technique I used was to fill the expansion take until I saw fluid in the bleed port as recommended by all bleed procedures that I read, but instead of continuing to pour to get the air out of the top of the radiator, I reached over and slowly squeezed the upper radiator hose, sort of like a turkey baster. This allowed me to control how fast the fluid/air was released through the bleed hole and thus control the mess. It also allowed me to force fluid into the upper voids of the radiator, forcing the air out. If you cover the expansion tank fill port while you squeeze the hose, it keeps the coolant in the expansion tank from flowing out of the fill port as well. It took a while to do but after road test heat up and overnight cool down the coolant level is perfect relative to the Cold line on the expansion tank.

This did not help figure out the problem with the overheating but when you get it figured out, it may help to avoid a mess on the garage floor.

[Mainthing]

I have a 95 318ti and had the same problem, I finally fixed it and my procedure was a little strange but it worked. I used a hose removal tool to purge the system. First I loosened the upper hose on the radiator and inserted the tool just to vent the system, i filled the expansion tank and blew into it, venting the hose at the same time until the air was purged , then tighten the clamp and refilled the expansion tank. Most important is to replace the cap. My temp reads straight up all of the time now, but I replaced the pump and thermostat to find it was the cap after I purged the air.

[socalxtreme]

Hello all, mine is a 96 328i and i just replaced my cooling system also, as well as the head gasket. Is it normal to have to put additional coolant in for the first 100 or so miles? Im getting a check coolant like once a week and have to add a pint or so. There is no leaks and no overheating at all. I have heard that maybe its the expansion tank that may be broken on the inside. It was a heck of alot of work and i'd hate to think that coolant is going somewhere it isnt suposed to...its definately got my attention because in the morning she stumbles for the first 20 or so seconds before she smoothes out. If anyone has any thougths about that please clue me in, its only been doing that since ive done the work to it. thanks alot.