BHG Question

[AjWit]

First off i do apologize because i know there are a ton of BHG threads, but i could not find what i was looking for.

Here's my dilemna, on the highway at 55 as i notice my temp gauge goes to half, my car normally doesnt get this high. I look down a moment later, and before my eyes it jumps all the way to about 3/4 on the gauge, i immeadiately pull over and turn the car off. Smoke is coming through the hood, i pop it open and more smoke pours out. No coolant leak, no oil leak! Radiator cap was ice cold, i mean really, it was colder than my hand, but the valve covers were steaming hot. I called a friend to bring a bottle of 50/50 coolant and we dump the entire thing into the radiator, it was thirsty. I start the car, it idle's fine and runs without a problem, well i mean besides the white smoke pouring from the engine bay and the exhaust. It looked like all the smoke was coming from the turbo though, which i found a bit weird. The car runs and drives with no power loss at all, i didn't get on it but i can tell that the power is still there. White smoke does pour from the tailpipe though, and the temp gauge stayed low the entire ride home, maybe 2 miles. Could this be a turbo, or should i stop hoping and just admit that it's a BHG.

If so, i have about 300 bucks to fix a BHG. Timing belt was done 20k ago with the water pump. So even though i probably shouldn't, i'd like to not replace the TB. I will not have money or tools to get the block surfaced, but it neccesary then i will get the head surfaced. Should i stick with a oem cosmetic HG since i cant surface both? And does anyone know where I can get instruction on doing the HG, i can strip a 7m down to the block, but i've never had to put one back together.

Instructions? and what parts to use for $300?
Thank you very much.

 

[AjWit]

bump in the name of i'm not sure i can tackle this with no insight

 

[pogoism9]

well, if your rad cap was cold, kinda indicates your thermostat didn't open. If this is the case, you could have in theory blown the head gasket. Does your overflow tank bubble like its boiling? Do you have air pockets in your system? Alot of questions that need to be answered to effectively diagnose.

 

[GrimJack]

White smoke out the back is typically a bad sign.

If you're desperate, you might be able to McGuiver it together for $300. The head needs to be hardness tested, if it checks out for that, it needs to be checked for straightness and possibly fixed. If it needs anything more than a very basic surfacing, you're going to be over budget.

If the head checks out, you'll need a head gasket and a bunch of top end gaskets. You should have no problems reusing the timing belt.

Put it all back together according to the manual with the exception of the head bolt torque - use 72 foot pounds instead of 58.

 

[AjWit]

overflow/resovior was normal, besides a dirt like substance, could be oil reminants but not sure. Smoke does come from the engine area as well when i start for a few seconds. No fluid in top radiator hose though, i found a auto machine shop that will do the work for 80-90 but i have to remove the cams and valves myself. I'm getting a spare head that i have checked tomorrow for warpage tomorrow, its already accessable as the manifolds, throttle body and every else is out of the car, but cam gears are still on. cams shafts in this one look really nice comapred to what they should look like.

Do you know if the head bolts are reusable, and if not then the cheapest place i can go to get them, i want arp's but they seem to be 100+ and i think i could use the money to get other things done. so i might buy a new set of stock bolts if they arent expensive.

The cam gears do need to be taken off with a pulley remover correct?

Thank you.
-Aj

 

[A70BoosTFienD]

just to be safe if i were u i would check the seals on the turbo... meaning check the piping for oil the stock turbo i believe has coolant running through it so there might be some of that too if the seals are bad. maybe..... that could be the problem but like pogoism9 said, more ?'s need to be answered to be sure

 

[pogoism9]

sounds like a thermostat failure then, what was your coolant mix like? Makes me think you boiled your water off, but that would almost require that you had way too much water and not enough antifreeze in it. Would also explain the spike on the temp gauge, if an air pocket passed by the sender. Either way, the 7M is not the best at handling ANY coolant related issue unless you are on a properly rebuilt engine (head torqued @ 72 on a stock gasket). In my experiences with the stock 7M, a single temp spike could prove to be fatal to the engine.

Others may see it different, and your mileage may vary.

 

[AjWit]

Ok thank you for your suggestions and insight.

Pogo: I will check the thermostat whenever i take it all apart to ensure it isn't stuck open or anything. I am leaning towards something malfunctioned for this to occur, i wasn't on higher boost and at the time havent had the tach beyond 3500 that day or the last. So i think something had to of occured to cause my BHG.

SupraHolic: I'm going to be replacing my turbo with a no shaft play lower mileage one from an 89. As well as all gaskets, i still havent ruled out the turbo being the problem completely, but i would like to get the head gasket done now that i've been planning on it.

So i know you need the change the oil after you change it, before you run it. Should i also flush the coolant system and possibly take off the water pump to make sure it's in working order?

 

[GrimJack]

Yes, you should flush the coolant system as well. Get the coolant system pressure tested, BHG tends to over pressurize the systems and pop the seals on the water pump. Seriously frustrating when you find this out after putting it back together...

You don't need a puller for the cam gears, just take out the bolt, slide off the timing belt, and they will pull straight off with very little effort.

There's virtually no chance that the turbo is leaking coolant into the exhaust. To the best of my knowledge, first of all, this has never occurred, and secondly, in order for it to happen the rest of the turbo would be obviously dead beyond repair long before coolant started to leak.

Stock head bolts are absolutely re-usable, ESPECIALLY if they weren't torqued to 72 foot pounds originally. Considering that the manual only calls for 58, chances are they are fine. Personally, I'd replace them with ARP hardware - but I'm not in the cash crunch that you obviously are.

 

[rayall01]

DEFINITELY get the arps, The stock bolts will stretch if you reuse them, and getting new stock bolts costs around $40.00. It's well worth the expense!