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Discussion Starter · #1 ·
Bought a Fleetwood Base Model 1989 with the 4.5L. Has about 66k and the last owner blew the HG. Looking to repair it with FelPro kit but any other kits out there that are reliable?? I also haven't been able to find a single 4.5L of this gen with a HG repair on this forum but I may not be looking hard enough. Any advice?
 

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1984 Eldorado Biarritz, 1983 Sedan deVille
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It is a conventional repair basically, just be sure to remove and reinstall the rocker bars evenly, and of course do not crank the engine for any reason with the heads off.

What are the symptoms of the problem? Much more likely to be an intake gasket leak than head gasket if there is water in the oil.
 

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89 Deville, 06 DTS
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It is a conventional repair basically, just be sure to remove and reinstall the rocker bars evenly, and of course do not crank the engine for any reason with the heads off.

What are the symptoms of the problem? Much more likely to be an intake gasket leak than head gasket if there is water in the oil.
Agree with the above poster, 4.5L head gasket failure is rare, especially at that mileage. What happened?

I have done the head gaskets on my 89 Deville (stupid radiator drain plug cracked and fell out, dumping my coolant on the freeway. Gaskets were gone by the time the idiot light came on….)

The repair is doable with the engine still in car, albeit space is tight. Getting the rear exhaust manifold off is a pain to wrap a wrench around.

Things to know/my recommendations:
1. There are 2 (3?) higher torque bolts on each head. Many other people have reported that these bolts strip upon reassembly. I chose to purchase the factory helicoil kit and coil the higher torque holes before I put everything back together. You may not want to do that, but understand the risk is there for thread damage. At the least, clean and chase the bolt holes before reassembly.

2. The Fel-Pro kit comes with MLS head gaskets. IMHO, these are fine for machine shop rebuilds. However, if you’re doing a repair with the engine still in car, find composite gaskets. The MLS gaskets have smaller tolerances that require a more perfect working surface usually only achievable if the head AND block are getting machined at the same time. I had the heads machined and simply cleaned the block. My composite gaskets sealed just fine.

3. Have the heads flux checked. The absorb the brunt of any overheating in this engine, and can crack if they do.

There weren’t many people, if any, who had posted about headgasket fixes in 4.5L motors. I looked, because I was most interested in whether or not it could be done with the motor still in the Deville. There were, however, more posts and videos about the repair on 4.9L motors, and is, for most purposes, the same exact repair. Try searching for those and you will find all the really helpful tips and tricks.
 

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Discussion Starter · #4 ·
It is a conventional repair basically, just be sure to remove and reinstall the rocker bars evenly, and of course do not crank the engine for any reason with the heads off.

What are the symptoms of the problem? Much more likely to be an intake gasket leak than head gasket if there is water in the oil.

Agree with the above poster, 4.5L head gasket failure is rare, especially at that mileage. What happened?

I have done the head gaskets on my 89 Deville (stupid radiator drain plug cracked and fell out, dumping my coolant on the freeway. Gaskets were gone by the time the idiot light came on….)

The repair is doable with the engine still in car, albeit space is tight. Getting the rear exhaust manifold off is a pain to wrap a wrench around.

Things to know/my recommendations:
1. There are 2 (3?) higher torque bolts on each head. Many other people have reported that these bolts strip upon reassembly. I chose to purchase the factory helicoil kit and coil the higher torque holes before I put everything back together. You may not want to do that, but understand the risk is there for thread damage. At the least, clean and chase the bolt holes before reassembly.

2. The Fel-Pro kit comes with MLS head gaskets. IMHO, these are fine for machine shop rebuilds. However, if you’re doing a repair with the engine still in car, find composite gaskets. The MLS gaskets have smaller tolerances that require a more perfect working surface usually only achievable if the head AND block are getting machined at the same time. I had the heads machined and simply cleaned the block. My composite gaskets sealed just fine.

3. Have the heads flux checked. The absorb the brunt of any overheating in this engine, and can crack if they do.

There weren’t many people, if any, who had posted about headgasket fixes in 4.5L motors. I looked, because I was most interested in whether or not it could be done with the motor still in the Deville. There were, however, more posts and videos about the repair on 4.9L motors, and is, for most purposes, the same exact repair. Try searching for those and you will find all the really helpful tips and tricks.

White smoke out of exhaust. Dumping coolant into my block and the coolant will bubble in the reservoir. I haven't been able to do any pressure tests though, so when i get it in the shop ill have to check for the intake gasket, fingers crossed that's the only issue but idiot last owner drove her until it smelled too bad to drive so...

@cksnyder what brand did you use? I don't have a problem with having my heads machined at my school, but would just like to consider my options.
 

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89 Deville, 06 DTS
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I believe I used a Victor Reinz gasket, $20 on RockAuto.

The intake manifold only briefly passes coolant through the front side (thermostat side) of the engine. No real issues with passing coolant from there to the combustion chamber. Even on the 4.1L engine, a leaky intake gasket usually passed the coolant on to the oil reservoir, which, ruining the oil, would wear out the cam lobes, eventually destroying the engine. My bets are your intake gasket is fine.

Make sure you get a FSM for this job- very much necessary.
 

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Discussion Starter · #6 ·
I believe I used a Victor Reinz gasket, $20 on RockAuto.

The intake manifold only briefly passes coolant through the front side (thermostat side) of the engine. No real issues with passing coolant from there to the combustion chamber. Even on the 4.1L engine, a leaky intake gasket usually passed the coolant on to the oil reservoir, which, ruining the oil, would wear out the cam lobes, eventually destroying the engine. My bets are your intake gasket is fine.

Make sure you get a FSM for this job- very much necessary.
FSM, is that something like ProDemand? Not sure what you'd be referring to otherwise, sorry.
 

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