cooling issues

2000 328Ci. Overheating

Expansion tank Cracked (Replaced)
Upper Plastic Radiator Hose Cracked (Replaced)
Radiator Cracked (Replaced)

I am wondering if its the thermostat, head gasket, or WP?

Is there anyway to find out directly without just randomly changing things? Any advice would be great.

Thanks

What's your issue?

Independent of your answer, though, replacing therm is always a good idea practically anytime! They fail open and closed and you'll see from reading even 5 of the 10,000 threads on cooling, that they're always replaced whenever doing ET or almost anything else. Cheap insurance.

It could be any number of things....looking into threads with cooling overhaul...many many around.

Lots of little details often overlooked.

Doug

Get the car hot, then feel the upper radiator hose. If it's really cool, the problem might be the tstat. If it's kinda warm but not hot it could be the water pump.

I've never used this check before but I think it could work. I might not be considering all possibilities, so you can complete the idea if you think this check'll help.

Also consider your aux fan and engine fan clutch.

fotsir, the upper hose is too hot to touch for any length of time. and the fan is electric, so an aux fan would be news to me. ill check for that in the AM. Thanks keep it coming ill try anything before making costly repairs

The thermostat will throw a CE code if there is anything wrong with it. You can take your water pump out and see if the impeller is still in one piece and spinning freely. Also if you changed some hoses and the expansion tank I would make sure that the system is bled; if there is air in the system the car will overheat.

When my therm failed open, it did not throw a CEL, so don't necessarily trust that. It may in certain circumstances, but it may not...I know it didn't for me.

Therm is a good bet, but you've replaced some things...safest, honestly, is to replace the rest...

Therm, any hose you didn't do...

Check coolant level...the first thing you should do...and do when cold in a.m....fill to between min and max.

On bleeding properly, search 'nearly overheated engine' I wrote instructions in that thread.

Anyway, don't piecemeal it at this point...go full bore...therm, WP...check pulleys and belts if you haven't done them for a few years...

Threads, diys on everything....could be temp sensor on lower hose...could be another leak...who knows, but cooling system comes in real handy.

You know not to drive car when needle goes above middle...turn off, get towed...srsly...or have $2500 or more for a fix handy...better spent elsewhere...towing is a pain, but better than $2500 and no car for a week or more...right?

Do not drive while it's above normal (dead center) on the temp gauge.

Doug