Daughter just kept driving...Help

[jake5]

So from best I can piece this together, my daughter had a belt fail. She did a good job of describing the events.
"First my heat stopped working"
"Then the car heat gage went to the hot"
"Then there was a giant pop and fluid and smoke was every where"
Ok so belt failed, water pump stopped (no heat), pressure built and the radiator (at the hose) blew apart.
Sooooo I need to start trouble shooting. My plan is to get the car in the garage, pull and replace the radiator, also possibly the pulleys if they show any wear or nicks that would of tore up the belt (it was fairly new).
Here is my big worry, Should I be worried about the head being blown?
Any thing else I should look for?
OHHH right. 91 e30 325 M20,
I have to get the car towed home befor I can get some pics up.

[george graves]

Ya might be lucky, and the hose blew before the head warped. Or not.

If it was me....I'd drain the oil, and look for water. If you had recently done an oil change, and don't see a drop of water or "foam" - you can put it back into the motor if you want to. If water didn't get into the oil, and there are still other issues. No need to do a oil change yet. You'll have bigger fish to fry.

Now if you see coolant/water in the oil, yea - you're in for some work. If it comes out clean, you might be lucky. New belt, inspect the pulley, re-tenstion it, fill the cooling system, and see how she runs.

If she runs bad, or blows smoke, then compression test each cylinder. Then you'll know if you've blown a gasket. You can also pressure test the cooling system, but I'm not sure there is a easy way to do that in a driveway.

Inspect all the coolant hoses. Including the ones going to the heater core. And looks for dampness on the driver's side floor board(leaking heater valve).

[jlevie]

Hmm, getting into the red and then the coolant explosion is usually a sign of more damage than just a blown hose. At the least I'd replace all coolant hoses, thermostat, water pump, and probably the fan clutch. There is a possibility that the expansion tank and/or the cap may have suffered damage, so I'd replace both.

It is likely that the overheat has warped the head and the gasket may have failed. If it hasn't already the gasket may well do so soon. So I'd pull the head, have it checked for cracks, then surfaced, assuming only minor warp. While the head is in the shop have the valves ground and guides checked for wear.

Once back together watch closely for any leakage of the radiator and heater core. Either of which could have been damaged by the overheat.

[MR E30 325is]

I would take George's advice before Jlevie.

J may be completely right in the end, but with repairs this complex/expensive/difficult to complete, taking baby steps is usually a smarter move.

I have had two E30's go into the red due to some issues, and blow coolant caps or hoses, and the head gasket suffered no ill fate. Immediately jumping to that conclusion without doing smaller checks is ill advised.

[gearheadE30]

M20s seem to be much more resilient to overheating than the twin cam engines; definitely check for water in the oil, oil in the water (if there is any water left) and do a leakdown test. Also, if there is any way to cobble the cooling system back into a sealed system without wasting too much extra time, a cooling system pressure test will also tell you if you've got a crack in the head or a gasket. Cooling system pressure test kits are available at reasonable cost on ebay, and they work fine. It only takes 10-15 psi.

If you blew the radiator before the pressure cap, you should also definitely replace the cap. Chances are it is gummed up and jammed, so it didn't relieve the pressure.

All this stuff takes a little time but doesn't cost much, and will tell you what you actually need to do to repair it rather than just throwing parts at it.

If you do have to replace the head gasket, follow Jlevie's advice and have the head checked while you're in there. I would hate to do all that work just to find that the head also failed after I put everything back together.

[george graves]

I have had two E30's go into the red due to some issues, and blow coolant caps or hoses, and the head gasket suffered no ill fate.

Yea when I was 18, I blew a hose on my e21 m10 - pin hole leak - didn't spot it in time. And Poof! Collant everwhere. I didn't know better.

Cooling system pressure test kits are available at reasonable cost on ebay, and they work fine. It only takes 10-15 psi.

If you blew the radiator before the pressure cap, you should also definitely replace the cap. Chances are it is gummed up and jammed, so it didn't relieve the pressure.

Good call on the cap.

Link to a pressure tester kit you use? 10-20 pounds you could do with a bike tire pump!

[gearheadE30]

Yea when I was 18, I blew a hose on my e21 m10 - pin hole leak - didn't spot it in time. And Poof! Collant everwhere. I didn't know better.



Good call on the cap.

Link to a pressure tester kit you use? 10-20 pounds you could do with a bike tire pump!

I have had cars and bikes with all kinds of different caps, so I went for this one: http://www.ebay.com/itm/262112675025...%3AMEBIDX%3AIT

If you really wanted to go cheap, get a piece of pipe and weld an NPT bung to it, and get one of those NPT to schrader valve fittings for a couple bucks off ebay. Pretty easy to make with basic fab skills and $10 of parts.

[jake5]

Thanks guys. So Finally after a few days of snow, renting a uhaul car hauler, and parts order waiting I have started work.
So here is my plan.
Drain Coolant and check , Done, Looks OK
Oil drain, Done, Looks OK, No water
Pull radiator Due to snapped hose Barb, Done
NExt.
Remove all remaining belts,
Check Pullies
Install new Radiator, Thermostat, Hoses, Belts
Change Coolant
Change Oil
Check Compression
Run it, Please run Ok, Please run OK, Please run OK.
New cap

[jake5]

Well, She ran good.
Only thing that kinda threw me. New coolant, New radiator, New oil, and it is cold outside.
I had to do some VERY spirited driving to get that thing up to temp. Good sign I guess. I thought my temp sensor was busted.
Any way....SUCCESS!!!! ;)
thanks for the tips.

[george graves]

Nice - just FYI, since the coolant sensors sits up high, they can be a situation where you have a large air bubble in the system, and you're not reading true coolant temps, but steam.

So, be sure to bleed the motor. You should have raw coolant coming out of the bleed nipple. Sometimes m20 and m30 motors can be a bit finicky to get all the air out - some times they will fix them selves by a few heating and cooling cycles. You can see if you have "air" in the lines buy squeezing on them. If it sounds like a midget having intercourse with a rhino, their might be air in there.

[straight6pwr]

If it sounds like a midget having intercourse with a rino,

you know, as hard as I try, I cannot imagine what sound you are describing here.

[superj]

That one is escaping me, also. I geuss post a link so we know