M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: RH318is on October 29, 2008, 09:32:08 PM
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These are two posts from my thread on another site. Any ideas/suggestions?
Had the car in for brakes and a wheel bearing and had the shop look at the cooling system as well because it had just started doing this - temp. would raise while sitting at a stop light. From about the 1/2 mark to in the middle between the 1/2 and 3/4 marks.
The shop said the following:
Coolant a little low, at the bottom of the reservoir
Pressure tested and found no leaks, but cap is old and leaking
After topping off coolant, test drove and temp. gauge was fine
Checked fan clutch, good
Checked thermostat via radiator hoses, good
Hoses and belts all looked good
Recommend new cap and coolant flush
In the end they topped off the coolant and put a new cap on. The car ran good for about a week, I noticed some liquid on the ground a couple days ago, touched it. Didn't feel/look like oil. Today, the temp. starts doing the same thing. Sitting at stop lights it's starts moving up.
Any ideas? Would a flush help? Could they have missed a leak?
What's the safest temp. to let the engine get up to before (seriously) worrying about a cracked head?
2nd--
Thanks guys. Some additional info I didn't have time for earlier. The same shop replaced the thermostat, fan clutch, did a coolant flush and replaced hoses I think it was 2 years ago. Yes, 2 years ago. According to the invoice I told them the car was running hot when sitting in traffic and too cool when driving.
Right now it's basically sitting at 1/2 way and then goes up when sitting still, definitely not running too cool.
What do you think I should do first? I don't really think it's leaking, I noticed some fluid after it had been sitting for an hour.
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First try bleeding it, there could be air in the system. Also check out that fluid. And if the engine is overheating in traffic or at a stop light and is fine when driving it will most certainly be the fan clutch. Also check your A/C fan is operating - this is an auxillary fan that cuts in when the engine temp is too high for the viscous fan to cool it down. Make sure it is operating by turning the A/C on.
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not exactly..
there is moving air into the engine compartment when driving...and the fan clutch has been checked...it should'nt be that...
look at tjts's "mess under the intake" there may be one of those hoses that are 17yrs old rotted and leaking..
thats what i would look at first...especially if the outter hose's arent visably leaking.
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Ok, here's a more accurate description.
First, with freeway driving the temp. gauge sits just under or right at the 1/2 mark (65-70 mph). Appears to perform normally.
While driving on city streets it's about the same right at or just under the 1/2 mark. When idling or sitting at a light the needle starts moving up usually to near/at the middle between the 1/2 and 3/4 mark. When I start moving from the stop light the needle moves back down to just under, or even slightly more, the 1/2 mark.
I do get hot air out of the heater.
I guess I can still drive it this way as most of my driving is freeway. The question would be what's the hottest temp. reading that safely away from cracking the head, up to 3/4?
The fan clutch was replaced two years ago along with the thermo., doesn't this sound like the thermo. might have gone bad again?
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Ok, here's a more accurate description.
First, with freeway driving the temp. gauge sits just under or right at the 1/2 mark (65-70 mph). Appears to perform normally.
While driving on city streets it's about the same right at or just under the 1/2 mark. When idling or sitting at a light the needle starts moving up usually to near/at the middle between the 1/2 and 3/4 mark. When I start moving from the stop light the needle moves back down to just under, or even slightly more, the 1/2 mark.
I do get hot air out of the heater.
I guess I can still drive it this way as most of my driving is freeway. The question would be what's the hottest temp. reading that safely away from cracking the head, up to 3/4?
The fan clutch was replaced two years ago along with the thermo., doesn't this sound like the thermo. might have gone bad again?
As simple as a thermostat is i doubt it went wrong. I'd go faulty gauge or faulty sensor.. Go buy a laser temp sensor from an auto parts store so you can shine it on your engine and coolant to see the current temp
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The shop recommended a coolant flush. Any value there? They did one 2 years ago.
What's one of those laser things cost? Just so I know what I'm looking for.
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I'd say the fan clutch is not working correctly or radiator is not cooling sufficiently being restricted (plugged).That would explain why when your moving along it stays normal (at the halfway mark).
Coolant flush may help .How much do they want for that ? I replaced the radiator in my car but it has 200K miles on it .
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Mine just turned 240,000 miles. The shop's recommendation was a flush, anyone else agree that flushing it may help. 2 years ago they charged $42.00.
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Mine just turned 240,000 miles. The shop's recommendation was a flush, anyone else agree that flushing it may help. 2 years ago they charged $42.00.
Just flush it yourself, it is messy, but it is not worth handing someone $42 to do imo. Flushing may help, but am I the only one who doesn't really see a real problem here? It doesn't, to me, sound like the car is running excessively hot, between 1/2 and 3/4 sitting in traffic isn't going to crack your head. I would flush the coolant, and as long as there are no leaks, and the fans are working as they should, leave it alone for a while. When you replaced the thermostat do you know what degree it is rated to open? I can imagine a 92C thermostat would read a bit higher on the gauge than a 88C or whatever the stock is rated at. Maybe its just me, but I wouldn't lose sleep over it.
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I have an 88 degree in mine and it sits a needle width above half and maybe a little bit more when I have the AC on. I don't think it should creep up like that when your sitting still ,at least mine doesn't .But like JL said if it doesn't get worse ,just keep a close eye on it.
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Check out my thread, Running hot, for more ideas. I had a cracked head and the car was running where your car is and a little higher. I would check to make sure your head is not cracked/ head gasket gone. Good luck with this problem.
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I took it back to the shop and they checked it out again. Said the temp/sensors and everything was/were about normal, so they thought it was probably the connectors on the gauge itself. Thanks for the advice.
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any more updates? mine is doing that too. did the clutch fan, thermostat, water pump, and most recently the radiator. my gauge however bounces when it moves. could it be the temp sensor? are those easy to do?
on mine the right side of the radiator doesn't get hot. the hose from the thermostat housing to the radiator is cool to touch. im assuming the engine doesn't even get hot enough.