[serioja123]

I check my coolant and it smells like exhaust. I rented a kit to check if there is exhaust in the coolant and the solution turn green but not yellow. Most likely the head gasket is blown, so if I will change the head gasket do I have to inset inserts for the head bolts?
Also I notice that the fans are working only when the ac is on, do any one know how to fix that?

 

[Submariner409]

What make, model, year of car do you drive? Please update your profile. Otherwise, guessing advice is futile.

 

[Harry Yarnell]

The headgaskets fail BECAUSE of the failure of the headbolt block threads.
The fan(s) won't come on til the engine temp gets up around 220°.
Fans on all time with A/C.

 

[Submariner409]

Harry, he drives a 2002 Seville (?? SLS - STS ???) I went back into his post history and there's a deleted post looking for Northstar studs or inserts.

serioja, Cooling fans run constantly when an A/C or DEFROST function is set. Otherwise fans go to SLOW at 224 degrees and FAST at 236. The engine cools to 213, fans turn OFF, the cycle repeats. fans do not normally run at over 30 - 35 mph. Not needed.

Your stud question - contact www.northstarperformance.com directly. You will NEED the correct GM/Cadillac service manuals for your car - engine work requires many special procedures and torques. Where are you? We might be able to recommend a good shop to do the head bolt thread machine work.

Inserts also are entirely satisfactory - look at www.huhnsolutions.com. NEW GM head bolts. Do not try to re-use the old head bolts.

Yes, you must machine and insert/stud ALL 20 cylinder block head boot holes.

Please update your profile.

Here's your temp gauge and fan sequencing.

 

[serioja123]

I just got a month ago 2002 cadillac seville sls

 

[serioja123]

I got the car in Seattle so I thought I will drive it to Sacramento, the car was fine drove perfect until I got to the mountains border Origon and California and the car started to overheat some light white smog from the exahuts and the fans did not turn on. I stopped checked the coolant and the coolant was there but after I open it was a smell like form exaust. I waited for a while then I drove to the nearest city always checking the enging temperature. Than the next day it was towed home. I went to Auto Zone and rent the coolant test kit and I test the coolent the blue solution turn to light green, so most likely head gasket is bad. I am planing to change it fith my father , he had some experince before with changing head gaskets but not on northstar engins. The car value is about $1500 so I do not want to spend much. I ask and to change a head gasked for northstar is about $3000 which is twice the price of the car))

 

[Harry Yarnell]

To do this job, be aware the powertrain and cradle need to be dropped. 'Impossible' to do from the top, though I've heard of it being done.

 

[Submariner409]

The main reason you got the car for $1500 was the required engine work.

If the car itself is in good to excellent condition with inserted/studded heads then it's "worth" more than $1500. Your $1500 buy-in was only the first payment on a long list of ownership payments. 20/20 hindsight, but - sight unseen - you should have had the car inspected by a reputable mechanic.

The car gets lifted off the powertrain and the head job is done either on the floor or with the powertrain up on a work table.

You can do inserts with the engine in the car but it's no fun - no fun at all. You cannot do studs with the engine in the car - no way to get the right (rear) head on - over the studs.

Start reading the stickies in the Engines; Northstar forum. You'll need the info.

https://www.google.com/search?sourc......0..0i131j0j0i22i30j33i22i29i30.pwRuK84QNiA

You WILL need the GM/Cadillac service manuals for your car and year. Too many special torques and procedures to try and guess - you WILL break something if you wing it - guaranteed. www.helminc.com or www.alldatadiy.com

Here's a pre-2000 Northstar on the floor.