Engine Super Hot after V belt renewal

[Mordan]

Hi,
I changed the spark plugs and the 2 V belts.

I drove a little and didn't pay attention to the water temp gauge. after 10 mins and a long slope, I look at it and it is in the red. (no lights or diode for letting me know??? )

I get off the road and stop the engine. I was told afterwards, I should have let the engine running and bring the heating to the maximum. any input on what to do when engine goes really high in temp?

The water level in the expansion tank is very very low. Here is what it looks like. Some water was leaking when I stopped the engine.



to come back home, I drove down the slope with the engine shut like a stupid noob. it was really hard to steer and brake. I restarted the engine because all of a sudden the brakes would not work anymore.

I got home all right and the only visible damage is this



nothing serious on this picture?

anyways I think I will change the water pump and maybe the radiator. I was told the water pump sucks on the M40 and could create havoc. How do you test your water pump?

EDIT: does this makes sense?: if the water pump is faulty, the water never gets hot and therefore the temp gauge always stays blue?

[anonymous1]

Hi,

The temp gauge will be showing you the engine temp, rather than the coolant temp so will still move into the red when the coolant is not being pumped. Have you checked to make sure the belts are on correctly and turning the water pump wheel as they should be? If this is all working, then I would look at changing the water pump - seems they are notoriously bad.

Here is a link to the procedure:
http://www.bimmernut.com/forum/showt...ght=water+pump

Make sure you keep an eye on the temp even after doing this in case something further has been damaged in the overheat. (Hopefully it won't have been).

May also be worth looking into changing the thermostat, hoses and the fan clutch if you are not sure on the vehicle history while your there, as you'll have access to them during this job.

HTH

[Mordan]

Here is a link to the procedure:
http://www.bimmernut.com/forum/showt...ght=water+pump


HTH

thx for the link. really good one. I will see tomorrow. and recheck the belt

can you check the impeller of a water pump or is it hidden?

I wanna buy this one

http://cgi.ebay.co.uk/BMW-530-530D-5...QQcmdZViewItem

but don't want to be ripped off with a plastic one.

as for the belt, the only itching thing is that the alternator is not perfectly in line. therefore the belt is a bit twisted



I checked the belts while running idle and everything is fine. clean sounds.

[Dave M]

thx for the link. really good one. I will see tomorrow. and recheck the belt

can you check the impeller of a water pump or is it hidden?

I wanna buy this one

http://cgi.ebay.co.uk/BMW-530-530D-5...QQcmdZViewItem

but don't want to be ripped off with a plastic one.

The impeller end is, for good reason, within the engine. I would stay away from ebay stuff unless you can verify it is in fact a good brand. Metal impeller is important, but not the only thing to look for. Someone here may know who makes a good one for the M40.

Hopefully, you haven't overcooked the headgasket or cylinder head. Do the pump and you'll soon see whether you need more work.

Dave

[e34.535i.sport]

FirstLine brand says the pic. water pump from dealer is 120 euros VAT included. This one is the third of the price. My question was if the seller tells me it is a metal impeller, can I check it when I recieve it?

what's supposed to happen if the headgasket or cylinder head is cooked? Can I still drive a few miles?

Yes you will beabletosee the impeller it should be on the outside so you'll know if its plastic or metal!

If you've done more damage you should look for coolant loss, milkshake on the oil filler cap, oil in the coolant and really rough running when first starting up. You'll be fine hopefully, mine overheated recently and I haven't had any further symptoms. Keep an eye on the temp guage - you don't want it happening again...

[Mordan]

The impeller end is, for good reason, within the engine. I would stay away from ebay stuff unless you can verify it is in fact a good brand. Metal impeller is important, but not the only thing to look for. Someone here may know who makes a good one for the M40.

Hopefully, you haven't overcooked the headgasket or cylinder head. Do the pump and you'll soon see whether you need more work.

Dave

FirstLine brand says the pic. water pump from dealer is 120 euros VAT included. This one is the third of the price. My question was if the seller tells me it is a metal impeller, can I check it when I recieve it?

what's supposed to happen if the headgasket or cylinder head is cooked? Can I still drive a few miles?

[e34.535i.sport]

as for the belt, the only itching thing is that the alternator is not perfectly in line. therefore the belt is a bit twisted



I checked the belts while running idle and everything is fine. clean sounds.

Looking at that picture the belt does seem like its on at an angle... I'm sure that's not right. Do you have a picture of where the belt is sitting on the other pulley? Perhaps its not on the correct rail? I'm not familiar with the m40 but if its similar to the m30 set up there are two places the belt can go on - one makes it 'wonky' and one lies straight.

If all belts/pulleys are working ok (and assuming water pump impeller is still in one piece), the overheating suggests that the thermostat got stuck closed... There's an easy way to check: Run the car to operating temp and if the top radiator hose doesn't get hot then your thermostat's goosed.

Good luck - let us know how you get on.

[Dave M]

FirstLine brand says the pic. water pump from dealer is 120 euros VAT included. This one is the third of the price. My question was if the seller tells me it is a metal impeller, can I check it when I recieve it?

what's supposed to happen if the headgasket or cylinder head is cooked? Can I still drive a few miles?

Ahhh, misunderstood you. The impeller in the auction pic is metal (plastic impellers are generally black). Whether its metal when it gets to you is another thing.

Dave

[Mordan]

Looking at that picture the belt does seem like its on at an angle... I'm sure that's not right. Do you have a picture of where the belt is sitting on the other pulley? Perhaps its not on the correct rail? I'm not familiar with the m40 but if its similar to the m30 set up there are two places the belt can go on - one makes it 'wonky' and one lies straight.

If all belts/pulleys are working ok (and assuming water pump impeller is still in one piece), the overheating suggests that the thermostat got stuck closed... There's an easy way to check: Run the car to operating temp and if the top radiator hose doesn't get hot then your thermostat's goosed.

Good luck - let us know how you get on.

it is night here. will do that tomorrow. I will let you know.

if the impeller is destroyed, should I see debris when I drain the coolant? now that I think of it, just a minute before seeing the gauge red, I heard tap tap tap tap tap during 10 seconds at 60 miles per hour then it disappear. I thought this must be the 'tappets' which I heard where sometimes making a sound on the M40. then the sound disappeared and I thought "I'm lucky". then again I never heard this sound before and never heard what the 'tappets' sound like.
anyways a minute after I saw the temp gauge lol. but i'm not sure when the gauge went up, because there is no bloody alarm. the light didn't even light up. does yours light up? *rant: there should be a sound alarm!!!

[Mordan]

to be complete, the only other thing I saw today after the over heating is the liquid out of the ventilation valve. is it boiling oil? why on the transmission?

#7
http://www.realoem.com/bmw/showparts...34&hg=23&fg=15