half a bhg?

[Clip]

i think it's finally BHG time.

here lately i've been losing coolant quickly and smelling it burning whenever i turn the car off and get out. today i went to test compression and see if i could find a blown cylinder. after warming up the car i noticed a large puddle of coolant underneath and traced it to the back of the engine. thought it might have been that 90* hose at the back but it was dry. is there a blockoff plate beneath it that might be leaking, or is it leaking from between the head/block like i think. i tried to get a look between the firewall and block with an insp. mirror but couldn't get a clear picture.

i've also heard the waterfall for a year now, but never had coolant in the oil or had the temperature gauge spike, never overheated. is that coolant leak at the back indicative of a BHG?

compression results were 176,175,156,178,188,180, doesn't look too far off the manual.

 

[AJ'S 88NA]

i think it's finally BHG time.

here lately i've been losing coolant quickly and smelling it burning whenever i turn the car off and get out. today i went to test compression and see if i could find a blown cylinder. after warming up the car i noticed a large puddle of coolant underneath and traced it to the back of the engine. thought it might have been that 90* hose at the back but it was dry. is there a blockoff plate beneath it that might be leaking, or is it leaking from between the head/block like i think. i tried to get a look between the firewall and block with an insp. mirror but couldn't get a clear picture.

i've also heard the waterfall for a year now, but never had coolant in the oil or had the temperature gauge spike, never overheated. is that coolant leak at the back indicative of a BHG?

compression results were 176,175,156,178,188,180, doesn't look too far off the manual.

#3 looks a little off. Maybe it's getting ready to really go. They should all be pretty close as far as compression. Did you check the little rubber cap under the #6 Exhaust outlet?

 

[Clip]

didn't realize there was a cap under there, i checked the manual but must've missed that one. is that on the passenger side of the block? i reached back and on the very back of the block (right against the firewall) i wiped oozing oil/coolant from it, i assume it was between the head and block (had my gloves on since the engine was warmed up to operating temps). i could also see coolant dripping from there onto the transmission and running onto the exhaust too.

 

[GrimJack]

Yes, passenger side, and it's only there on the pre-89 model.

 

[Clip]

ok, mines an 89. didnt think i overlooked that

 

[cuel]

EGR cooler is back there, but I don't recall if it has coolant running thru there. Could be where the heater hose nipple goes on the back of the head as well. You could get it up on stands, undo the trans. cross member, lower the trans, and look up there with a flash light. Put some dye in the coolant to make it easier to find the leak.

 

[LordLo]

I had that. Waterfall noise for a year and it never overheated or had the mixing of any fluids.

I finally got fed up with the noise and decided to change the hg; and that fixed it. Turns out only one of the coolant passages on #6 decided to go, so that allowed combustion pressures to get into the coolant system... so not worth the headgasket change.

 

[CRE]

I had that. Waterfall noise for a year and it never overheated or had the mixing of any fluids.

I finally got fed up with the noise and decided to change the hg; and that fixed it. Turns out only one of the coolant passages on #6 decided to go, so that allowed combustion pressures to get into the coolant system... so not worth the headgasket change.

I had the same occur. Definitely worth doing the HG at this point. Exhaust gases are caustic and will only lead to more headache if allowed to continually contaminate the coolant.

 

[suprarx7nut]

Agreed that if you can afford the down time, just do the head gasket and do all the other misc. maintenance with it. Change most the coolant hoses and such and clean everything real well.

 

[Frank Rizzo]

EGR cooler CAN leak coolant. Why do you think they call it a cooler? What do you think is cooling the exhaust gases?

If any of you have ever taken your 7M's cylinder head apart, you can plainly see how coolant passes by the EGR cooler. There is a 17mm allen head plug underneath the EGR cooler that will leak if overheated enough. But you will not see it leak externally unless the EGR cooler gasket is blown or the M6 bolts that hold the EGR cooler on are stripped out from the heat.

I would put money on the 32mm heater union. The heater union uses some kind of aluminum alloy sealing washers instead of the usual copper sealing washers.

 

[Clip]

time to dive in, then. i suppose i'll go ahead and pull the engine to make the changes easier, i'm going to freshen up a lot of other stuff as well. plus i've got another car i can DD. thanks for the confirmation!