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Discussion Starter #1
Hi.
Well as posted in the title, I'm having problems with my E46 330D saloon. I bought it privately last year from Birmingham and it's turned into a real lemon. but with work, I'm finally winning.

The latest problem is to do with the water temperature. The car was taking in excess of 45 minutes to warm up and if you had the heater on, it never did. If you blocked off some of the radiator it did reach normal 12 o'clock position. Easy diagnosis I thought, change the stat.

I did that the other day with a non-genuine (already regretting that one) replacement from Eurocarparts.

Didn't have any real problems and completed the job. Then added anti-freeze and water and bled the system as per the guide on the forum. I noticed quickly though that the water in the expansion tank was very foamy and looked like washing up liquid. There was also a pulse on the top return hose which at a regular interval blew air then returned to water for a few seconds, then the cycle repeats.

I though it was an air lock and that it would self-bleed although I noticed this morning on my way to work the temp gauge never goes past 1/4 now. At work I ran the engine cold with the top off the expansion tank and the return to the tank was a continuous stream. Perfect.

Having just got home from work (temp gauge only reached 1/4), I now have the pulse in the top hose again.

Is this just an air-lock or have I missed something really stupid? Why is the gauge only 1/4? Have I got a faulty stat?

I'm really out of idea's. Any help would be brilliant.
Thanks,
Scott.
 

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Discussion Starter #3
Thanks for the suggestion Ali but that wouldn't explain the fact that it got to the middle on the original stat and now it doesn't on the new one. Or the fact that there is so much air in the system. Any other ideas?
 

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Try bleeding the cooling system again, and let us know the outcome :thumbsup

How to bleed the cooling system.
1.Jack the front of the vehicle up onto stands as high as possible,
2.Turn the ignition on to Aux 2, Engine OFF, heater on fan setting 1 and temperature fully hot,
3.Remove the rad cap/expansion cap,remove the bleed screw from the radiator and IF you have them the bleed screw(s) from the thermostat housing/top hose, return pipe or EGR thermostat.
4.Fill the radiator/expansion tank up and keep pouring till there are no more air bubbles coming out from the bleeds, using a funnel that fits tight in the expansion tank neck and filling it full of water will help push any troublesome air out, when good you can then install the bleeds and tighten down(don't snap them),ensure the rubber O-rings/seals are still on the screws/on the bleed holes.
5.Suck some water out so it's not full to the brim, start the car up and check coolant shoots out of the small hole on the inside of the expansion tank neck when the revs are held up, if it does then replace the cap and then run the car up and check for heat from the vents when the car is warm, then carry on and check if over heating still persists. You may have to bleed troublesome cars again afterwards.(but very rare).
6.If all is good then check the water level again in the morning when cool.

or

Ignition on, heater set to hot, bleed screw out.
Pull the top hose off the radiator. Pour coolant SLOWLY down the rad hose a litre at a time. When the coolant is building up in the hose, hold it above the level of the rad hose stub and keep adding it. When coolant starts to dribble from the rad, refit the hose. You may find that coolant starts to overflow from the rad cap orifice - if it does, just screw the cap back on. Once you've done that, the engine and radiator are full of coolant - the little air pockets that might be left will come through the bleed screw.

After the vehicle is bled you should check that when the revs are held up you get a flow of coolant shooting out of the hole in the inside of the expansion tank neck, this will help tell you if the water pump is circulating, then run the car up and check the lower radiator hose gets hot. You could also get a "block test" performed to tell you whether the headgasket has gone.
 

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Discussion Starter #5 (Edited)
Thanks for the reply Ronnie.

I have managed to sort the problems out on the car. The foamy return water and pulsing in the top hose of the rad were obviously air in the system. I sorted this out by getting my car on ramps on my steep driveway so that the front of the car was as high as possible and followed your instructions. I couldn't clear the pulse in the top hose but a short but vigorous drive sorted that out and my needle returned to the 12 o'clock position.

Having got to grips with the hidden OBD, i found that my water temp never got beyond 71 so like other members, replaced the EGR stat which got my water temp to 91 which I'm really happy with.

For reference, I got the stat from Blue Bell BMW in Wilmslow. They charged £33.80 inc. VAT. I also replaced the bleed screws at the same time, i noticed the plastic had begun to age. They cost £6 for 3.
Williams ordered the parts specially and got them as promised same day and at a reasonable price. I cannot recommend them enough, I even found out my car is an import!

Anyway, thanks for your help. My next job is finding out what's causing the lumpy tickover! BMW's are fun!
 

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Good to hear the thermo problem is sorted, your lumpy idle could simply be the MAF sensor deteriorating.
Try disconnecting the electrical plug to the MAF and see if it cures the idle?

Failing that you'd need a diagnostic scan for any errors and live scan to monitor the correction on the injectors. INPA can do both :thumbsup
 

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Discussion Starter #7
Apparently the MAF was replaced with a Bosch unit roughly 12 months ago, but I'll try your suggestion Slowtech. Not sure why but I have a feeling it's an injector.

Ordered an Ediabas lead so I should be able to sort out the diagnostic scan soon. Will keep you informed of progress!
 

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Apparently the MAF was replaced with a Bosch unit roughly 12 months ago, but I'll try your suggestion Slowtech. Not sure why but I have a feeling it's an injector.

Ordered an Ediabas lead so I should be able to sort out the diagnostic scan soon. Will keep you informed of progress!
Do that pal, I've INPA running so if you're struggling at all drop me a line :thumbsup
 
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