View Full Version : 2002 Deville HG Replacement

04-26-08, 06:41 PM
WEll it seems I may need to do a headgasket replacement on my '02 Deville Base with 148k. I have not done any testing yet to confirm this but with my current knowledge about it I believe there may be no way around it.

On Friday I drove to work in the morning, and the car overheated for the first time since I owned it. On my lunch break I added 50/50 dexcool mix to the system while it was reletively cool, and filled the reservoir to the fill line, it was roughly 3 quarts low. When I went to leave work, the car would not start, although the starter was engaging, it definetly seemed like a piston was hitting a brick wall of coolant.

I have recently noticed some "excessive" white smoke for roughly 1/2 mile of driving after I start the vehicle, but I recently (2 weeks ago?) switched from regular mobil 5w-30 synthetic to Mobil HiMi 10w-30, and also put in a can of Justice Brothers Oil Treatment. I figured the smoke was from the high amount of detergents in my oil "cleaning something" out.

I will update on the condition of my car, it is being towed to my house soon.

Does anyone know if you can do the heads without dropping the motor? I am thinking no....

Also, have any of you out there written a procedure for this?

One more question....how many specialty tools are required to strictly pull the motor, R&R the HG, and get it running again? Looking for info on things such as cam locks, etc. The stuff you never think about.

I am pretty sure I am am going to be elbows deep in shiite on this one, I appreciate the help. I am looking forward to my first American DOHC V8 engine job, I think it will be fun.

Thanks guys

04-26-08, 10:50 PM
Ya it sounds like you are toast...

Keep in mind that 2002 Northstars have a TSB on the water pump cover... The cooling system leaks here and will drip on the tranny bell housing and evaporate... This will look EXACTLY like a failed head gasket. But this one only costs about $40 to fix and is an "easy" DIY project...

I suspect that most of the 2002 failures are as a result of not noticing this very slow leak and then having the engine over heat...

Mine was losing about a 1/2 a quart a month... and I was scared about the head gaskets... During one oil change I noted a drop of collant on the bell housing... Discovered the TSB and replaced the pump cover...

It has not lost a drop of coolant since. :hide:

04-26-08, 10:53 PM
Do an exhaust gas test on your coolant, its pretty rare to see a blown hg on an 02. And replacing a northstar hg is far from fun.

04-27-08, 09:54 AM
Come on! Taking a motor out to do headgaskets isnt fun!? Sounds about as fun as doing a clutch on a 944 turbo, you only have to take everything apart, which only take 20 hours (to do a clutch....yaaaaaaaaaay):bighead:

I still have yet to do testing on it yet, yesterday is was snowing and blowing here in Minnesota (YAY! It's almost May! I love snow!)

I am going to start with pulling the spark plugs, as the motor will not turn over which leads me to believe it is hydrolocked. BOOOOOO!

04-27-08, 10:01 AM
All is not lost though, I get a new car out of the deal! Any suggestions anyone? My budget is about $15K. This is what I currently have in mind, as I like very big cars (because I am 6'2" 145 lbs :D) and need to haul a canoe to one of minnesota's 5,500 lakes with fish in them. The other 12,000 I am going to stay away from.

Another Deville, maybe an 05. 06's are usually over $15k

A cheap SRX?

A CTS, even though i think the top of the line CTS (not the V) looks NO different to me then the cheapest one you can buy.

Or else no more cadillac.....There are many many other good cars out there, right?