e46 question

[gravyface]

Posted this at e46fanatics, figured you grizzly veterans can chime in here too.

Looking to add something newer to the stable; need something a little more modern when visiting clients (my boss says I look like a Jamaican drug dealer in my 318iS) and to give me an option when the e30 is under the knife.  Anyways...

Looking at purchasing an '01 325i manual that's currently experiencing overheating at idle, but "runs perfectly" on the highway (quotes from seller).

Car has 200k miles on it.

Seller has no service records -- calling the dealer and doing a VIN lookup shows that it was last serviced by an authorized BMW dealer in 2003.

Price is a bit less than bluebook value, and I'm confident I could talk him down a grand or so -- coupled with an ECS Tuning Cooling System II overhaul, I think I could have a really nice car on my hands for cheap.

Problem is, I'm not sure the extent of the overheating damage -- was the car shut off in time? Head gasket failure? Warped heads?

Keep in mind, I'm a novice mechanic at best (I've changed plugs, oil, and wheels, that's about it), so I'm looking for a sure-fire way of identifying whether there's been any permanent/expensive damage at all or whether it's a thermostat, faulty fan, relay/fuse, etc. Basically anything below head gasket failure I'm going to pull the trigger on the car; anything more than that, I walk away.

Also, I don't mind spending a bit on getting an inspection so if you think that this would best be left to a pro with proper tools, lift, etc. please let me know what kind of test I should be asking for (I've heard "block test" being tossed around in the forums).

[Geoff]

most times,  if a car overheats at idle but not at speed, it has a crappy radiator in it,  one that can do ok when air is rushing thru it, but not enough cooling when there is no air.  You cant really know for certain if it overheated, but you could get a compression test done.  If that checks out, it means your head gasket is good, and your cylinders are sealed up pretty well,  and most probably there was no heat related damage to worry about.
                                                                Regards,
                                                                      Grizzled;)

[gravyface]

The e46 apparently has a crap cooling system period -- plastic impeller on the OEM water pump, exploding expansion tank; there was a recall on the aux fan as it could overheat the circuitry and fail.  The overhaul kit is $350 and well worth it from what I've heard, so yeah, I'm ok with putting a bit of money into improvements, but if the head gasket failed/is failing, or the head's warped, then no.

So a compression test should show good, consistent numbers across all cylinders.  Anything else I can look for while I'm there inspecting the car?

[d.hitchcock]

Hi, hope you don't mind a noob speaking up. I have a 2000 323i Touring, 5-speed, which we love. If the car is right, I predict you'll really enjoy it.

BUT ... I'd haul that sucker to a dealership and cough up the money for a thorough PPI.

If you don't feel like doing that, find another car.

Too much risk of engine damage ...

You can scare up comparable cars for fairly low prices all day long on Craigslist.

Cheers,
d.hitchcock