Head Gasket Problem? 1990 Cadillac Deville

[jaypmba]

I had recently purchased a 1990 Sedan Deville with just over 122K miles for a few hundred dollars from an independent dealer -- it was a former trade in. The body is straight and the interior is nearly new with a few signs of wear on the driver side. I also pulled a CARFAX report and everything checked out okay as far as I can determine. Upon inspection of the car I knew the car was going to need a good tune up and a new radiator. The fluids all checked out okay but due to the neglect of the radiator it definitely needed to be switched out. However, the car doesn't leak whatsoever and the body is straight and the interior is nearly brand new. It started up just fine and it ran nice and quiet. However, it did have a little bit of a miss ---- especially when you tried to accelerate but I had attributed to it needing a tune up. Again, I already made an informed decision to buy this car knowing that it was going to need some work --- some of which I can do myself unless it's serious engine work.

I plan to use this car as a second mode of transportation as an ocassional driver or for long travel and as a weekend get around car that I plan to invest some time in --- plus I love the 1989-93 era Cadillacs Devilles. During the week after purchasing the car I would drive it around on ocassion to the grocery store to get a better feel for the car. As the week progress, the missing became more pronounced, more sputtering, and now was going through some hard starting. I pulled the codes and basically it was related to the oxygen sensor and distributor. I changed out the oxygen sensor but the problems continue. What really raised my concern was going up a grade; the car would sputter and backfire if I apply more pressure on the gas pedal....but if I barely apply pressure or drive slowly it would go up the hill but without all of the sputtering and missing. At idle (parking or neutral), it appears to run smoothly. But when at a stop light, it would idle but a bit rough as if it wanted to cut off. Otherwise, the car seem to run and function fine with no warning or check engine lights coming on.

I went to this websiste (cadillacforums.com) and did some research and also purchased the Haynes repair manual. After further investigation, I was somewhat convinced that the car needed a major tune up and some fuel emission work. I never thought it could be a head gasket related issue since there's no sign of white smoke or a mixture of coolant and oil. However, I had a mechanic take a look at the car yesterday for a number of hours. The initial prognosis was that too much fuel was getting into the cylinders and that the car was actually being run on six cylinders! Moreover, the spark plugs were all foul. However, it was later determined that the car had blown a head gasket and all the cylinders needed to be resurfaced plus it need a valve job (plus a new radiator). The cost? $3,000!

Considering the initial investment into the car, $3,000 may not be a big deal considering that the car will essentially be new and the shop does guarantee their work (and they have a solid reputation in the community as well as AAA recommended). However, I also thought that perhaps I could just cut my loss and spend a third less on a 1993 model that's in much better condition given their blue book value.

This is dilemma and would need some guidance or thoughts:

1. Is $3,000 too much for a head gasket job?
2. Should I cut my losses and move on?

Right now my thought is to get a second opinion. It's difficult to accept that it's a head gasket issue since the signs were not apparent nor consistent with the typical head gasket signs. The car has never overheated since I had it. However, I would not rule out that maybe the head gasket was preexisting prior to purchase but the fluids never indicated as such upon my initial inspection. Moreover, the coolant never overflow into the reservior. However, I willl admit that I haven't had the car long enough (only a week) to determine whether there's an internal leak or not. Either way I do have the money to get the job done but I'm thinking that I might be better off buying a 1993 deville for that kind of money or less that's in much better condition.

[misfit6794]

3,000 isn't that much for a head gasket. I've heard dealers charging up to 4,000. I just blew mine in a 96 Deville. Make sure the mechanic thats doing the head gasket knows what he's doing, you don't want to spend 3,000 on a shoddy repair. If the car is in great shape, like my Deville, I'd say fix it. You won't really be able to get that much for your car, and if you plan on buying another caddy, plan on another head gasket. Make sure you get a second opinion though to make sure its the head gasket and your not getting taken.

[gta3mobster]

I also recently purchased a 1990 4.5 Deville for the same purposes that you posted. I was going to drive my 1994 Grand Prix daily in the city (better gas mileage) and use the Deville when I needed to haul people on long trips.

I haven't had the same problem with the Deville, but I have just recently started having the same problem you have with my Grand Prix. With the Grand Prix, when I am driving on a highway, accelerating up a hill, the car feels like crap; almost like it's misfiring, but not quite. It feels terrible... Not sure what it is, either.

122k miles is not very many miles for the 4.5L engine from what I've read. I bought my 90 Deville with 194k miles on it and it seems to be running just fine.

You say the spark plugs are foul. Did the shop replace them? The ACDelco +4 plugs seem to be the best plugs to go with. Have you cleaned the throttle body and EGR valve?

Maybe these threads will help you: http://www.cadillacforums.com/forums...procedure.html (90 4.5L Idle Learn Procedure?)
http://www.cadillacforums.com/forums...ction+reaction (1990 DeVille has" the shakes" and revs on its own)

Also, get some GM TEC (top engine cleaner) and give that a shot. See if it gets rid of any carbon buildup.

If you only paid a few hundred and the car isn't giving any codes, with only 122k miles, why not just go ahead and try to get it tuned up and see if that helps.

Was the mechanic someone you know and trust, or was it just a shop trying to screw you out of money? Also, 3000 is nuts. You can spend $3500 and get a whole Jasper engine with a warranty (I hear they're really good engines too).

And whats says that the 93 that you want to buy doesn't have any problems? Any car that old is going to need repair.

[jaypmba]

Thanks, Mobster for the response.

I plan to go to the shop today. They have not started the job yet. Depending on what they say and upon review of the plugs, etc. I may decide to have my car taken elsewhere for a 2nd opinion. This particular shop came highly recommended based on my review of the BBB as well as a third party publication. I do like the fact that they guarantee their work but $3K seems a bit high; however others who have responded to this thread or others all seem to conclude that a head gasket job is around $2K and up. I need to get further clarity as to what's involved in the pricing. If the $3K includes the new radiator, values, hose, tune up, belts, etc. then perhaps that may be a good deal. But I'm still unsettled about this being a head gasket situation.

Yes, I have thought about cleaning out those parts you'd mentioned and that was my intent when I took it to this shop --- to basically get an assessment on the missing since I wasn't able to narrow the problem. Although I can do some minor tune up work there are some things that I'm limited on due to a lack of specialized equipment, time, etc.

[jaypmba]

Originally Posted by misfit6794

3,000 isn't that much for a head gasket. I've heard dealers charging up to 4,000. I just blew mine in a 96 Deville. Make sure the mechanic thats doing the head gasket knows what he's doing, you don't want to spend 3,000 on a shoddy repair. If the car is in great shape, like my Deville, I'd say fix it. You won't really be able to get that much for your car, and if you plan on buying another caddy, plan on another head gasket. Make sure you get a second opinion though to make sure its the head gasket and your not getting taken.

Thanks, misfit. I will get a second opinion regarding the head gasket issue. I'm leaning towards getting the car fixed regardless but I want to spend the money on the problem rather than a possible speculation. In essence, these mechanics will have to convince me that the car needs a head gasket especially when the signs aren't apparent.

[misfit6794]

Does the car overheat at all? If it was a head gasket it would get hot pretty quick and stay hot. The oil would also be milky. Coolant would also be in your tailpipes, hence the white smoke, and the coolant will also come out the overflow. Your right to get a second opinion and not just throw parts at the problem. If your head gasket is going, it will pretty much ruin new spark plugs and o2 sensors. Also are you having to add any coolant?

[Ranger]

A 4.5 may well have milky looking oil if the head gasket is gone. It should overheat or be using coolant. Does it do either? How did they come up with the head gasket diagnosis? Coolant hydrocarbon test or cylinder pressure test?

As far as your decisssion, the one thing I can tell you is that the '93 will have a 4.9. More powerful, and much more reliable. They will run forever.

[jaypmba]

Originally Posted by misfit6794

Does the car overheat at all? If it was a head gasket it would get hot pretty quick and stay hot. The oil would also be milky. Coolant would also be in your tailpipes, hence the white smoke, and the coolant will also come out the overflow. Your right to get a second opinion and not just throw parts at the problem. If your head gasket is going, it will pretty much ruin new spark plugs and o2 sensors. Also are you having to add any coolant?

The car never overheated since I had the car and I brought it about a week ago. I have not had to add any coolant; however, I haven't driven the car a lot due to my concern about the radiator. But based on the 30 mile drive from the dealer last week the car operated just fine.....except for the symptoms as I had described earlier.

I just came back from the shop and spoke with the mechanic who looked at the car. His explanation for the car needing a head gasket seems plausible and somewhat consistent on what I've researched and my assessment of the engine's general condition. However, I plan to get a second opinion from another mechanic after this weekend.

[jaypmba]

Originally Posted by Ranger

A 4.5 may well have milky looking oil if the head gasket is gone. It should overheat or be using coolant. Does it do either? How did they come up with the head gasket diagnosis? Coolant hydrocarbon test or cylinder pressure test?

As far as your decisssion, the one thing I can tell you is that the '93 will have a 4.9. More powerful, and much more reliable. They will run forever.

During the 2nd visit to the shop, the mechanic said that he ran a compression test on all 8 cylinders. The cylinders all pass just fine on the compression. He performed a number of tests including the cylinder pressure test. That test alone validated (along with the excess fuel going into the cylinders) for him that the head gasket needed to be replaced. He also showed some bubbling in the radiator ---- another sign. And when he replaced the spark plugs the car actually ran better......but it started idling rough again due to the build up. Although I did not see any smoke coming out of the tailpipe, he claims that he saw some coolant drippings coming out of it. He did not check to see whether there was an issue with the vacuum during his investigation into the car but he thought based on the condition of the car that it was actually tuned within the past year.

Based on what he has now shared I'm somewhat more accepting that this could be a head gasket problem but part of me is still skeptical. I mentioned that the car has not overheated --- no smoke or warning lights from the dashboard. Perhaps, it's possible if the pressure test is any indication.

I did get a quote on the job as follows:

$1407 labor
$900 value job
$100 gasket
$430 radiator
$30 fluids
$100 hoses
$40 spark plugs

And this doesn't even include the cost of new heads if they need to be replaced. And the radiator cost is way too high. Boy, I wish I can go to my regular trusty Honda mechanic but he said that he doesn't work on American cars.

If the 2nd opinion confirms what I need then I plan to go ahead and get it fix. However, I think I can save at least $500 on the total from a reputable shop.

[Ranger]

"He performed a number of tests including the cylinder pressure test. That test alone validated (along with the excess fuel going into the cylinders) for him that the head gasket needed to be replaced. He also showed some bubbling in the radiator ----"

That pretty well confirms it. I doubt you'd need new heads.

[misfit6794]

I agree, my heads are getting machined and will be like new ever though i blew a head gasket, heads should be good.

[lovedembigcars]

good points on this post about the heads but i have one possible solution.

check your fuel regulator. Located right underneath where the intake begins.. i had the same problems you were posting (stalling out, random high idle speeds and rough running), changed it out and was good to go. Costs about 60 bucks but well worth it. also check the boot on the exhuast flange where the headers meet the cat, it may need some replacing if it sounds like an airboat when you get down in it..

[jaypmba]

Originally Posted by Ranger

That pretty well confirms it. I doubt you'd need new heads.

Thanks, Ranger. I'm becoming more accepting of the fact that a head gasket job will need to be done. As far as the heads, the general consensus from the mechanic was that it's very unlikely the heads will need to be replaced. Others on this board has said the same as well.

[jaypmba]

Originally Posted by lovedembigcars

good points on this post about the heads but i have one possible solution.

check your fuel regulator. Located right underneath where the intake begins.. i had the same problems you were posting (stalling out, random high idle speeds and rough running), changed it out and was good to go. Costs about 60 bucks but well worth it. also check the boot on the exhuast flange where the headers meet the cat, it may need some replacing if it sounds like an airboat when you get down in it..

Thanks, B.C. That I can definitely do myself and it may be worth a shot.

[noahsdad]

Four points and a suggestion:

1) The evidence you've been shown would not be enough to make me agree to a $3g head gasket job. You have none of the classic symptoms such as milky oil or white smoke. Fouled plugs caused by coolant should produce clouds of white smoke.

2) Did you actually see bubbles in the rad during the cylinder leakdown test? Bubbles can happen without a blown HG. Also, bubbles from a bad HG are usually accompanied by an oil intrusion or exhaust smell in the coolant.

3) How do they know the heads or cylinders will need any resurfacing until they have it apart? Also, these engines cyllinders cannot be 'resurfaced,' they must be re-sleeved. That's essentially a total engine teardown and rebuild.

4) You mention in the first post that the radiator was neglected. This likely means your engine was likely not given the single most important maintenance item required by the 4.x series - GM coolant sealant supplement.

Suggestion: If you have a bad HG it wouldn't be a surprise.GM has had head gasket problems since the early 1960s right through today. (Actually, the same is true of every manufacturer of aluminum block engines.) The 3.4 v-6 in my wife's 2003 Olds van just had them done at 41K. However, since you're looking at a total teardown and rebuild at this shop, you won't do much more damage by replacing the rad, flushing with distilled water, and refilling with 50/50 and the GM sealant supplement. Give it a tuneup, drive it awhile and see what happens. If the HG really is bad, you'll know soon enough - in which case I'd be tempted to buy a crate engine and just have it replaced. The money would be about the same, you'd get it back in half the time, and then you would have a new car. But if your HG isn't bad, you might get away with $300 or less.