[grafton]

After some hard use one night my 2008 E90 335d with 70k miles on the clock, is now losing coolant (head tank capacity)



The car was driven about 12 miles the following day with not enough coolant in the system (foolish i know, but done now )



do you think that has cooked the EGR or the head gasket?

[cm335d]

Originally Posted by grafton

After some hard use one night my 2008 E90 335d with 70k miles on the clock, is now losing coolant (head tank capacity)



The car was driven about 12 miles the following day with not enough coolant in the system (foolish i know, but done now )



do you think that has cooked the EGR or the head gasket?

---
Are you spewing any white smoke? Also, did you pull the dipstick and see if it looks like chocolate milk? I doubt it is the EGR Cooler. How fast it is losing coolant and how much?

[rkstar9]

one good way to see coolant leaks is to remove the under tray and look from the bottom. any dried off dripping of coolant by the front of the engine compartment accumulates under hoses and stuff and forms a white residue.

[grafton]

yeah there is steam coming out of the exhaust pipes

the car lost a header tank full of coolant in 25 miles of normal driving, i filled the header tank to the brim with the float right up and then after 25 miles the dash warning came on

when i parked up the header tank and float was back down to the bottom

i did check the oil, the oil looked dark but ok, (oil and not thick sludge but ill check again now)

[grafton]

ive checked again this morning, and re-topped up

there is water vapour/steam and small water droplets being spat out down between the air box and small turbo into large turbo

coolant is being sprayed onto the inner wing and foil heat shield etc

the plastic belly pans underneath have water lying in them, and the steering arm gaiter running to the front wheel, the plastic corrugated gaiter is wet/splashed

and the opposite side of the engine bay (passenger side here in the UK), lying on the ground the belly pan underneath the car/engine is wet showing spray further back, as if its leaking from the passenger side of the bottom of the radiator too

[rbreding]

Originally Posted by grafton

coolant is being sprayed onto the inner wing and foil heat shield etc

If you can see coolant being sprayed it would seem logical to start there and then hose off the engine to see if/where else there is additional leakage.

[grafton]

its the first time that ive been able to check in daylight, as ive been busy working etc sorry

[rbreding]

No worry. Start there and report back.

[grafton]

so long as its not the head gasket, i cant afford the £1700 - £2500 thousand repair bill, that is almost exactly 25% the cost of the whole car 3 months ago

surely the belly pans wouldnt show any trace of water if it was the head gasket

there would be no external water spray or traces anywhere surely

the car still drives as good as gold

[ptpending]

the leak near turbo is egr and main thermostat with water pump
there is also plastic and rubber connections going from them to the left side

[cm335d]

Check both of the coolant hoses that go to the EGR cooler. The bottom one comes off of the water pump into the EGR cooler and the top one loops it back in. Both of those are plastic quick connect fittings and after a few years get hard and crack.

[grafton]

after stripping down earlier today, the egr take off from the exhaust manifold between the two turbos was loose, the 2x T45 torx screws were only finger tight at best, not rattling or anything but defintietly not tight enough, which would explained the gases/exhaust fumes i could see being blown out

how do i seperate the plastic thermostat connection that runs off on the left hand side of it that runs via the hose to the middle of rad half way up, ive seperated the right hand side thermostat main pipe connection with the QR clamp, that one was easy enough, but the left hand side one has a QR, which i have disconnected but the pipe seems to be being held in with something else and feels locked firmly in place even though the QR spring clamp is completely removed and out

the egr thermostat is dated june '07 on the date stamp, so im renewing for brand new GATES items the egr thermostat and main thermostat (also dated june '07 on its plastic date stamp marker)

also im tempted to put back in a different EGR cooler, second hand off ebay etc, the one that was on the car currently looks to have gotten real hot and also had melted the bottom part of the EGR thermostat where the yellow rubber ring sits, it was all melted and deformed and then obviously had cooled solid again, i suspect where it has gotten so hot in the past it may well have a hair line crack inside it somewhere