[riotten22]

Hey guys,

I have a 2008 BMW 335XI within the last month it has overheated 3 times. I drive 30 minutes at hwy speeds then within a minute or so of exiting the hwy the Yellow temp sensor then the red. Today I had my logger on and watching the coolant temps and at hwy it fluctuated between 188-205 then just as i started exiting the hwy it started going up all the way to 250 and the yellow and red coolant lights came on. I pulled over shut car off for 2 minutes and restarted and it immediately calms back down to low 200s. It happens so quickly after hwy speeds it doesnt seem likely that it is a fan issue and I have checked fans at idle and they are working. Does this sound like symptoms pointing to a failing Water Pump ? Anything else i should be focusing on ?

Thanks for your input.

[jt335i]

It would appear the water pump is beginning to fail. Have the cooling system checked as soon as possible before you get that dreaded yellow warning light soon to be followed by the catastrophic red light immediately telling you to pull over.

[catcher22]

How many miles do you have?

Your waterpump and thermostat may need to be checked. Check your codes, that will help narrow down the problem.

[riotten22]

Originally Posted by catcher22

How many miles do you have?

Your waterpump and thermostat may need to be checked. Check your codes, that will help narrow down the problem.

Is there a certain way to get the codes? I have a cheap obd scanner and it doesnt show any codes. 107,000 miles

[mweisdorfer]

Originally Posted by riotten22

Is there a certain way to get the codes? I have a cheap obd scanner and it doesnt show any codes. 107,000 miles

If you have the original oem water pump & t-stat, you don't need a code reader for this DIY. I'd say your t-stat is probably on its way out. Your water pump is in the top 5% of all water pumps that make it past 100,000 miles. In this case, change out the water pump, T-stat & U shaped pipe that connects both.

If the you are on your 2nd water pump because your first one was changed at around 75,000 miles chances are decent the t-stat wasn't changed out at that juncture. So, again the t-stat is toast. In this case, change out the t-stat & U shaped pipe.

In either case above, if you are on the original oem coolant or don't know how old the coolant is, do a coolant flush. Liqui Moly makes a great coolant flush.

If you want a good code reader for just BMW's, buy the Schwaben/ Foxwell scanner.