spattie

So I've had a small coolant leak somewhere in my car, I've been keeping an eye on it, but it's starting to get pretty bad so I'm going to get it fixed. It only seems to leak right after I shut the car off, so I've come to the conclusion that it is leaking at the secondary water pump (had mechanic look at it). The car also started running poorly (no power) when the leak started to get bad (squirting). The check engine light was on (it flashes if you accelerate too hard, this is new), and the mechanics device said that ETG's have gone bad, sending the car into "limp mode". Now I was originally thinking I need to replace the water pump and the ETG's, but I think it's probably not coincidental the ETG's went at the same time as the water pump. Is it possible that the fluid squirted out of the secondary fuel pump (it was squirting all over the engine), and onto the ETG's, causing them to get some messed up temperature reading, and coincidentally put the car into limp mode? The car runs fine (not limp mode) sometimes, but it seems to go into limp mode after the fluid squirts all over the place....

donromani

Short answer, no - the egt's are housed inside of the turbocharger on the "hot" end and I think they only cause limp-mode when they read too hot, not the other way around (I might be wrong though).

I would replace or delete the secondary water pump and see if the EGT errors go away. The EGTs are extremely expensive, so don't swap them out unless you need to.

DxC

sorry to hear of your issues, but these are audis - they do require maintenence ... and if you leave it and ignore it it wont go away by itself



your car also needs EGTs or the EGTs turned off in the ECU. again, a common maintenence issue on the s4. FYI a flashing check engine light means misfires, which is likely separate from the EGT

as these cars are all 10 yrs old now - all the common issues will surface, along with more fatigue related things ( brittle plastic in engine bay, sensors failing due to hot engine bay, etc) ... luckily the knowledge base for the car is pretty good. s4wiki.com is a great place to read up - ive literally owned over 50 b5 s4's and they are interesting!

PS - the braintrust and really valuable members have migrated elsewhere.

spattie

do you think it's possible that the coolant was squirting onto the coils/ wires causing it to misfire, and the check engine light to flash? The coils and wires in the car were recently replaced...