Funny cooling problems

[Rompsku]

Generally BMW engine rooms don't have much space in them, especially 6cyl vehicles! so basically there isn't much space for the heat to disperse. Also, the engine compartments are quite well sealed, so there isn't much room for the hot air to escape.

I've had 2 E36's, an E30 and an E46, all 4 cars were noticeably hot under the hood after a good drive. In my opinion its quite normal not to be able to touch the expansion tank after the engines been running for a while.

Why would you want to? :rollsmile:

The fact that your temp gauge is normal is a good sign.

As for the thermostat, turn on your heater to full, if the air is warm then you're ok.

All gauges are perfectly normal. No coolant loss, heater and aircon works fine. Performance still feels like it's all there.

HOWEVER... the white smoke is getting worse, and the car seems to be using about 500ml of oil after 1000km. Changed the oil less than 1500km ago and it's also leaving very small (size of a R2 coin) oil patches in the driveway if parked there overnight. Oil also seeping onto exhaust headers causing oil smell in the cabin.

There's no oil in coolant or coolant in oil, no milky sludge in oil. Is this still signs of headgasket?

 

[Kyle]

Generally BMW engine rooms don't have much space in them, especially 6cyl vehicles! so basically there isn't much space for the heat to disperse. Also, the engine compartments are quite well sealed, so there isn't much room for the hot air to escape.

I've had 2 E36's, an E30 and an E46, all 4 cars were noticeably hot under the hood after a good drive. In my opinion its quite normal not to be able to touch the expansion tank after the engines been running for a while.

Why would you want to? :rollsmile:

The fact that your temp gauge is normal is a good sign.

As for the thermostat, turn on your heater to full, if the air is warm then you're ok.

All gauges are perfectly normal. No coolant loss, heater and aircon works fine. Performance still feels like it's all there.

HOWEVER... the white smoke is getting worse, and the car seems to be using about 500ml of oil after 1000km. Changed the oil less than 1500km ago and it's also leaving very small (size of a R2 coin) oil patches in the driveway if parked there overnight. Oil also seeping onto exhaust headers causing oil smell in the cabin.

There's no oil in coolant or coolant in oil, no milky sludge in oil. Is this still signs of headgasket?

Ok so there's clearly an oil leak, I wouldn't go straight into assuming its the head gasket. Check easier accessible gaskets like tappet cover,oil filter, sump etc.

 

[wikk3d88]

Work through the cooling system sytematically and in a logical fashion. At its age and mileage you should probably replace all the cooling components as they are a known issue on the E36

If your HG has blown you really shouldn't still be driving the car.

 

[Pfw28]

Opened up the radiator I replaced to show to the customer and found... Not a lot, but also the cause of this problem. The tanks had sludge up to the 3rd pipe, packed solid, above that, all open. BUT! Coated all over with lime scale and a little rust. Seems that when water is heated, carbolic acid is forced out and reacts with other salts in the water to form lime, or chalk. This is a REALLY good insulator, and prevents cooling. A little more Google showed up that this can be cleaned with a vinegar treatment, so I'll try it on the open one and pic the results. Post tomorrow, after science lesson. Your symptoms sound like a blown head gasket, but what caused it to blow? The oil leak above the exhaust is probably the tappet cover gasket, they get hard and brittle, not likely related to the head, except that the extra heat hardens then up more.:fencelook:

 

[Dippies]

One way to test the thermostat is to let the car idle and if one of the bottom and top water pipe differs in them its not opening. :rollsmile:

Glad you found one problem at least with the Radiator.

 

[Doomsdaya]

Seeing that we both have a "96 328i & similar problems, I might as well add my loooooooooong story here...

Last week while doing oil & water checks, to my surprise the expansion tank was empty :dropjaw: topped it up with water, let it idle till it was operating at normal temp & took her for a drive to check pressure. At the garage I noticed slow drips of coolant from under the car but the temp gauge was at midpoint. Seeing that I was taking my car on Friday to recon the alternator, might as well get the cooling system sorted.

Yesterday was D day, I left my car with the auto electricians to sort my alternator & cooling system. Came back in the afternoon & was told the bearings in the alternator was worn out, so they replaced that but the hose from the radiator to the thermostat had a crack & no spare shops were open, so they put duct tape to seal the leak :facepalm: Anyway as I got home, I parked the car off & the OBC was giving me a check coolant level :thinking: Opened the bonnet & saw coolant was oozing from the expansion tank cap :banghead: Now I thought to myself, either the cap wasn't closed properly or the tank is F**ked but I left it as is & didn't touch it because the engine was extremely hot & left it for the next day.

Today I went to inspect & indeed those f**kers didn't close the cap properly & once again the tank was empty I topped it up with water & decided to take it for a drive to monitor how much coolant would leak. 2km away from home I saw the temp gauge just under the 3/4 mark & going up :banghead: I immediately pulled over & switched off to let it cool down. Surprising though was while it was cooling down I didn't see any leaks :thinking: An hour had passed & was consulting with Riaan the Fish on whether I should risk driving it home or let it cool completely because it was getting dark & I was parked in a dodgy area :mmm:

Decided to take the risk & was advise to drive very slowly with the heater at full speed (for some reason no hot air was coming out) :dunno: Anway while I was crawling my way home with my eyes fixed on the temp gauge, it was at the midpoint most of the way until a couple meters before my driveway, thats where it started going up to the 3/4 mark. By then I was home :woot:

So its got me thinking :thinking: how long does the plastic thermostat & radiator last ??? because while the car was with the previous owner, the thermostat was replaced about 3 years/30,000km ago & the radiator 7 years/100,000km ago or it could be the water pump thats fubar

 

[LPM320]

@Doomsdaya: You say that the expansion tank ran dry. Did you bleed the cooling system after replacing the water that was lost?

 

[Doomsdaya]

@Doomsdaya: You say that the expansion tank ran dry. Did you bleed the cooling system after replacing the water that was lost?

No I didn't :facepalm: I'm such an idiot for not doing so :floggin: Does this mean the head is toast :banghead:

Btw where is the breather screw ??? I tried looking for it from top to bottom

 

[Pfw28]

Btw where is the breather screw ??? I tried looking for it from top to bottom

Depends on which type of radiator you have, the one with the seperate bottle is self bleeding,no bleed screws, according to the Bentley manual. They say all E36 6cyl are this type. The other bottle(1pce with the rad, 4cyl) has the screw next to the filler cap, you can't miss it.

 

[Doomsdaya]

Thanks dude, I haven't used the car all week but have noticed the expansion tank is now halfway :bangdesk:

I checked the dipstick & oil cap, so far no signs of toffee...

 

[Pfw28]

No toffee is a good sign, but not definitive, just means no link between water and oil. The head may well be leaking into a cylinder from the water jacket, no oil involved. If this is the case, it's dangerous on start up. Hydraulic locking bends conrods, if much water has seeped in while standing. Only way to be sure is a pressure test, :fencelook:

 

[LPM320]

As long as the temp needle didnt go into the red, everything should still be ok...

The beeding screw is right next to the filler cap. Doesnt look like a bleeding screw, but more of a fastner to attach the tank to the radiator...

 

[Doomsdaya]

As long as the temp needle didnt go into the red, everything should still be ok...

The beeding screw is right next to the filler cap. Doesnt look like a bleeding screw, but more of a fastner to attach the tank to the radiator...

At first I thought that screw was meant to hold the tank to the body and no I didn't let the needle go past the 3/4 mark...

 

[sclass]

thanks for the input pi328!

Have the car for little over a month, it's my second BMW (had a E30 325i).
Everything under the bonnet get super hot, more so at the front of the car. I can barely touch anything connected to the radiator. But my temp never goes over the halfway mark, not even once. And that's what worries me, I'm scared the car is somehow overheating but the temp needle doesn't actually show it. Is that possible?

I don't think I'm leaking coolant, car stands in the garage all day, only really take it out at night, and there is not a drop of oil or coolant anywhere on the floor. Haven't had to top up coolant since I flushed it about 2 weeks ago. Have done about 400kms since then.

What are all the symtoms of a head gasket leak? I get the white smoke and seems to be a airleak on intake side of engine (creates a wooshing sound). But I'm not loosing coolant, power still feels like it's all there and the car generally runs and idles perfectly. Should I be worried?

The waterhoses do get hot. They also get taut but they SHOULDN'T be rockhard, you should still be able to squeeze them somewhat...