: question about N* headgasket



hheabe
01-30-05, 03:29 PM
HI. Can anyone tell me if you have to pull the engine, on a 1994 Sedan DeVille, to replace the front headgasket? It has the 4.6L N* engine. It has an external antifreeze leak and I am assuming it will need a headgasket and thread repair also. Would like to know if anyone knows if there is enough room to do all the work with the engine in the car. Thanks alot for any help!!

BeelzeBob
01-30-05, 11:28 PM
Diagnose the leak before ripping into it. It would be unusual for an external leak of coolant to be a head gasket. Could be....but usually a head gasket failure on a Northsar is an internal leak at the fire ring into the cylinder.

Pump the system up when cold with a cooling system pressure checker and find the lead source.

The water crossover casting bolts to the rear of the engine/cylinder heads at two places on each side so if there is a leak at the water crossover/head or water crossover/block interface it would show up like you indicate.

If there is an external leak of coolant and that is the only sypmtom I would drain and refresh the cooling system with fresh 50/50 coolant/distilled water and add a dose of the cooling system supplement/sealer. It is excellent at sealing an external coolant leak like you describe even if it is at the head gasket interface...unless you really just want to pull the cylinder head....LOL. Remember to put the supplement into one of the rad hoses, NOT the surge tank.

If you do the head gasket you can change the head gaskets with the engine in the car. The front bank is realatively easy but the rear is pretty difficult in the car. Can be done but not easy. In either case you will have to pull the front cover off to access the timing drive to remove the head so that makes working on it in the car a little harder.

hheabe
01-31-05, 04:37 PM
Thanks alot for the reply! I am planning on digging into it further, so I can make sure it is the headgasket or not. I DEFINATELY don't want to do the headgasket just for the fun of it!! It isn't leaking into the engine at all , it is just external , so I am hoping it may be the crossover that you said. Thanks alot. I am also looking for a factory GM service manual for this car if anyone knows of one. Thanks

BeelzeBob
01-31-05, 10:39 PM
Thanks alot for the reply! I am planning on digging into it further, so I can make sure it is the headgasket or not. I DEFINATELY don't want to do the headgasket just for the fun of it!! It isn't leaking into the engine at all , it is just external , so I am hoping it may be the crossover that you said. Thanks alot. I am also looking for a factory GM service manual for this car if anyone knows of one. Thanks


Put fresh coolant in it and when the rad hose is off to dump the old coolant out pop 6 or 8 or the GM coolant supplement pellets into the hose....drive it and forget it.

mcowden
02-04-05, 04:33 PM
I am also looking for a factory GM service manual for this car if anyone knows of one. Thanks

You can get the FSM here:

http://www.helminc.com/helm/product2.asp?class%5F2=CAD&mk=Cadillac&yr=1994&md=Deville&dt=Shop%2FService+Information&module=&from=result&Style=&Sku=GMP94EK&itemtype=N&mscsid=8F8M2JJ970DV8PRTPLD29P2R8WE65XX0

Or just go to http://www.helminc.com and search for item number GMP94EK. It's listed for $30 right now. That's not too bad.

Good luck...

hheabe
02-05-05, 10:15 PM
Hey, thanks alot for the info!!! I will check out the manual. I will gladly pay $30 for it. Thanks again.

chevyorange
02-12-05, 01:56 PM
You can get the FSM here:

http://www.helminc.com/helm/product2.asp?class%5F2=CAD&mk=Cadillac&yr=1994&md=Deville&dt=Shop%2FService+Information&module=&from=result&Style=&Sku=GMP94EK&itemtype=N&mscsid=8F8M2JJ970DV8PRTPLD29P2R8WE65XX0

Or just go to http://www.helminc.com and search for item number GMP94EK. It's listed for $30 right now. That's not too bad.

Good luck...

Thanks for the tip! I for some reason thought these were closer to $100.

I picked one up for my STS!

Great tip. :D

Adam

Ranger
02-12-05, 05:43 PM
Thanks for the tip! I for some reason thought these were closer to $100.

I picked one up for my STS!

Great tip. :D

Adam
They ARE over a hundred dollars. More like $125 but I think Helm is cleaning house and running a sale on '95 and older manuals.

chevyorange
02-12-05, 05:44 PM
Incredibly excellent!

On its way - paid for!

Thanks again.

Adam

mcowden
02-12-05, 11:31 PM
No problem... Glad it worked out. Let us know how it goes!

chevyorange
02-18-05, 05:14 PM
Arrived today, in two hefty beautifully bound editions. Can't believe this much good stuff for $30! HIGHLY recommend anyone getting on this deal if you're thinking about it before they're gone or the price goes up.

Can't wait to do a little reading here. The books on the spines have the classy model year and Cadillac emblem embossed in gold.

Thanks again for the heads up, probably the best $30 I've spent in a long time.