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Discussion Starter #1
Hi *,

currently I'm doing a head gasket job on a L27/Series I/HJB due mixing of coolant with engine oil plus white smoke from the exhaust. It's a 1991 Buick Park Avenue with 150k mi. I already did the LIM gasket twice - to be 100 percent sure - but no luck :icon_conf

After removing the front/left head I noticed corrosion on the block. Probably coming from the non-covered/overlapping gasket part:



After cleaning:



I think this will run into future problems. Is this common for this engine? Can I keep it as is? I checked it with a straight edge: Surface is even.

The rear/right head is a real pain (I dare more to come). I can't remove the drive belt tensioner because of that heater pipe going into the timing cover. How do I get the damn pipe out without bending it? The bracket is attached to a stud and this one goes throu the tensioner into the head. I tried to twist the pipe but no luck - like welded.



Regards

Gammablitz
 

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Good Luck trying to remove that pipe.

Just maybe, you can use a dremmel, and cut the pipe. You may then be able to
use a slightly larger pipe with J-B weld to re-seal it.

You may also consider using hydraulic hosing to couple the connection.

I worked on an L27 on our 1995 Transport. Lots of fun......

Cheers
 

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One question for you..... when you replaced the lower intake gaskets, was there any coolant in the lower intake manifold? If there was, there's a good possibility the UPPER intake plenum has rotted thru at the EGR pipe. This allows coolant into the manifold which would cause a lot of your symptoms..... Head gasket issues are somewhat rare on 3800's..... but not impossible. Also, when you pulled the heads, were any of the head bolts looser than others and how did the old gaskets look?? Jake
 

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Thanks for your suggestions gtx500hp.

I sprayed WD-40 to the sealing/connecting end of the pipe and let it soak a day (couldn't work on the car anyway). Today I tried to twist and it broke loose. Using a locking pliers I bent the bracket over the stud, twisted the pipe a little near to the head and was finaly able to remove the stud/tensioner. The pipe is still in the timing cover and I wasn't able to get it out. Must be a hell of an o-ring.



@Jake:

(Luckily) the 1991 got the metal UIM w/o EGR system. After removing the intake the second time (engine ran just a few minutes) I checked the gaskets but they looked fine. Today I checked the LIM and it's .0015 warped on the right side. Therefore I expect the problem will be the right head. At least the intake ports are even.



It's got lot of pitting but the sealing surfaces are nearly fine. I'll better try to seal the pits with some JB Weld. The previous owner obviously ran the car with old coolant for many years. The termostat housing looks more worse, but it still seals fine. I don't think the .0015" will cause leakage, does it?

With your words on mind I tried to remove the bolts of the right head. Some were defintly looser than others (also some rocker arm bolts - some were completly oiled up, they should be coated with that old orange/amber thread locker) but I wasn't able to remove the second head bolt (counting the torque order) the socket slipped. The last bolt ... :icon_mad: Gotta buy a new socket before I start over.

This is the left gasket:



Looks okay except the rust, doesn't it?
 

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Discussion Starter #5
Meanwhile ...

Still no luck using a new socket ... slipping, but not round :icon_mad:



I'll clean that area with a wire brush and hope WD40 will help a little. Pray for me (and the 3800).
 

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I don't see any tell tale sign of where the coolant was mixing with the oil.
Mr. Goodwrench has much more experience in this area.


The mating surfaces look okay to me. THe head gaskets are both intact with no signs of failure.

Hopefully you can get that stuck head bolt to free up. You may be able to force a smaller metric socket on.

I pray very often these days. I will say some prayers for you. Ask St. Anthony for some help..;-)

CHeers
 

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My best guess would be cylinder 3 had some coolant coming in. It looks cleaner than cylinder 1.
 

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I pray very often these days. I will say some prayers for you. Ask St. Anthony for some help..;-)
Thanks. I'll try again in 7 to 8 hours :icon_surp

My best guess would be cylinder 3 had some coolant coming in. It looks cleaner than cylinder 1.
Good catch. Indeed something was going on at number 3. I noticed some kind of «cloudy appearing» intake valve:



Probably the green shine might be coolant. But the picture is taken with a flash. Might come from the ripped graphite coating. And that spark plug of #3 looks lean:



Probably leaking a little, but on the other hand the gasket's fire rings look near fine.
 

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Still need to see the rear head. You must of caught this before the engine oil looked like a milk shake.

Like Mr. Goodrench said, pretty uncommon to have head gasket failure on 3800
engines.
 

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Hey, when you get that new 6 point socket for the stuck head bolt..... heat up that bolt before trying to loosen. Usually doing this the bolt will expand and contract(after cooling off). Then go after it with a good 6 point socket. Lets assume the bolt turns a little but not completely free...... at that point, douse it with WD40 and let it soak for a few mins. Then try again. Once it starts to move, stop and re-apply WD again and repeat the turning of that head bolt. Turn it both directions and continue to apply WD. Once you get it move a little back and forth, you should then be able to wrench the bolt out.

I'll pray to the car Gods for you! Jake
 

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Discussion Starter #11
Thanks for praying ... success! I jammed a worn 14 mm socket on the bolt head was able to slightly turn it. Also thanks to the WD-40 Company.

Jake, we've to talk about my exhaust manifold bolts on my '75 T-Bird. The manifold needs new gaskets ;)



Threads of that stuck head bolt:



Anti-seize? Hell no. But bad news for me ... the right head and cylinders are fine:



No sign of burning coolant or a leaking gasket. I've been warned ... 3800 gasket usually don't fail. I still have to check the mounting surface, and the machine shop for cracks, but ... damn.

btw, everything started with a failing water pump. The bearing started to leak and spilled the coolant out until I noticed the engine heated rapidly up. I knew the cooling system was shot (rust and gunk inside) and decided to flush and clean it using citric acid. It was filled with an unknown red coolant. Probably not suitable with the gaskets and cast iron - who knows. I feared my cleaning method removed important sealing areas, that are just sealing because they where clogged. Probably someone already used some sealer or mixed coolant types. Everything inside was coated with that gunk - it wasn't chalk. The citric acid removed all that stuff and brought back a shiny look. Also the by-pass hose leaked:



I keep posting and do more pictures on the work I do. Might be helpful to other people with the same problem on that engine.
 

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Discussion Starter #12
Just checked the right head and it's warped by .002 inch. The shop manual states a maximum disortion of .004, fel-pro (for their PermaTorqe gaskets) .003 inch. Well, it's still within spec. Block isn't warped.

PS: My other post got eaten by the spam filter (again). Thrilling what causes this.
 

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Are you planning on a valve job and head resurfacing?
 

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Hey, I noticed in one of your pics there were two head bolts partially rounded head. In the future and when you reassemble, use a 6 POINT socket. 12 point ones just won't cut it if the bolt is stuck pretty hard..... like those shown in the pics. Also, when you reassemble, use some oil on the bolt threads and the base of the bolt head where it contacts the head surface. This will allow easier and more accurate torquing of the head bolts. Another thing that works well for torquing is using "anti seize" on the bottom of the bolt head. This will also allow smoother and more accurate torque results. I agree the slight head warpage is no big deal from what you mentioned. But I'm not completely sold on felpro head gaskets over the OEM ones. Pretty sure either will do the job with correct torque. Lubing the head bolts during assembly is also a very good idea. Sometimes I will chase the threads in the block with a tap just to be sure the threads in there are clean and good for best accuracy during torquing along with that lube on the threads.

One other think to consider....if you look at OEM torque specs and proceedure, there is a first pass torque and the second pass is in degrees. This process is what they call "torque to yield". Re using this type of bolt over again is not such a good idea(because it's already been stretched to yield correct torque). That being said, it's a good idea to use new bolts. I would use an after market bolt set like ARP or something similar. At bare minimum new OEM BOLTS. (The ultimate would be studs and matching nuts/washers like ARP or another aftermarket brand) The good part of these bolts is they can be used over again unlike the OEM "torque to yield" bolts. If there are any other techs on the site they would agree with this concept. Either way, use new bolts.....

When it's all done give us another shout to see how it all turned out.
Jake
 

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Discussion Starter #15 (Edited)
Are you planning on a valve job and head resurfacing?
Yes, both. But I let the machine shop do the work, cause I don't have all that tools to check valve guide and stem clearance/wear and probably other stuff.

But I decided to remove, disassemble and clean the lifters. It was a good decision!



The outmost first and last lifter got damaged rollers - i. e. intake on cyl #1 and #6. It looks very bad on the picture but you nearly can't feel it. All others are fine except some rollers don't spin very well. But I'll recheck after the brake cleaner dried. I think dirt oil came down and flow right between the cam and roller that crushed it. I still have to check the camshaft for damage ... :icon_conf

I thinking about to change all lifters and push rods. What's a good brand? Mahle? Melling? Sealed Power? Enginetech? GM/ACDelco OE lifters would carge me $ 345,48.
 

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I really appreciate your posts Jake.

I already got new Fel-Pro head bolts. They are coated with sealer and anti-seize under the bolt head. Looks like the original GM bolts had the very same on it. It's that dry stuff that looks like red/blue threadlocker on ready-to-use bolts. Go with it, or lubricate additional? Fel-Pro says to not lubricate. Getting ARP products over here is near unpossible or I have to pay lots of shipping costs. Tried already to get intake manifold bolts ... around $ 100 in total. I'll use some generic grade 5/8 bolts.

Unfortunately GM canned the support for the L27. OE head gaskets are out of stock since 2009. The only steel/graphite gasket came from Apex, but I never heared anything good from them. So Fel-Pro is probably the best you can get for the L27 or LN3 and earlier. Mahle sells «nitroseal» gaskets ... don't know about it.

Cleaning the threads is done:



I ensured an old bolts goes in without any resistance and waddles a little. Only one hole had to be cleaned with the tap. I used a little handtool with engine oil on the tap and cleaned all with brake cleaner afterwards. I think they are fine for now.

The torque order from the Fel-Pro installtion sheet and from my GM shop manual is identical:

1st: 47 Nm/35 lbs ft
2nd: 130°
3rd: 30° inner four bolts

btw, should I install new (shorter) push rods? OE should have 7.989". Sealed Power offers 7.9650 and Enginetech 7.9630. I think both heads will be milled with .1 mm - thats minus .0394 inch. Therefore I'd need 7.9496. Of course the lifters will compensate a little, but how much?

For generic work-in-progress:



That's the crud sucked out using a small hose and syringe. It's just from the left block. Tasty. Oh and btw, that shiny stuff isn't gold - just dried ;)
 

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Discussion Starter #17
Allright, checked the cam and it got the very same damage on #1 as the roller :icon_mad:



#6 seems fine. I picked out a little chip. Feels like plastic.

Forgot another WIP:

The intake manifold got «welded» using J* Weld. I cleaned the pits using a needle and was surprised how deep some of the pits go. I used a razor blade for applying. Works pretty well.



btw, this is the lower thermostat housing:



Always chance your coolant :icon_surp
 

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Discussion Starter #18 (Edited)
The Buick is doing fine for some while so I think it's time for the

conclusion:

Doing the head gaskets was probably not necessary. Cylinder 3 showed some signs (bright(er) piston and that cloudy appearing intake valve), but I cannot say this condition was due burning coolant. Before doing the job I suggest to do a compression and combustion leak test. But ... well ... I had bubbles and smoke coming from the radiator (but had not done a leak test). It's really strange, cause the head gaskets looked okay.

The discovered black plastic chunks came from the (not longer existent) protection hose of the ECM/AC harness. Looks like a shop or previous owner didn't take care of it and parts fell into the valley while doing a LIM change. I found lots of chunks after removing the lifter guide retainer. Some made it into the push rod seats of the lifters as well.

btw, I installed new Sealed Power HT-2148 lifters (Made in Mexico) and RP-3285 push rods (Made in USA). They are of good quality. The push rods have the same length as OE.

The Fel-Pro head bolts worked quite well. No jumps, no squeaking. The dry lubricant works too ... using another new 9/16 six-edged deep hex socket ;) Things are getting complicated if you're using a vanilla torque angle gauge on the right/rear head. I had to use the video cam of my cell phone to adjust the zero-degree setup and to verify the current angle. Wish I had an electronic Kent-Moore.

Another side note: The o-rings of the injectors seem to get porous. I had two injectors with rubber parts in the built-in filter. One ring was really nasty looking, the other five were okay.

Thinking all about this and before installing the intake manifold I decided to ensure the sealing surfaces of the heads are really as fine as I thought. I took an old gasket, put white paint on the silicone and pushed it against the head. Guess what ... the lower sealing lips at the coolant ports hit the deep rusty canyons. I did only a picture of the left head, the right head looked far more worse.



I cleaned the corroded areas using a scriber and fine steel wire brush as good as possible. That almighty J* Weld did the final repair job.



Of course cleaning the cooling system using citric acid removed a lot of rust and the gasket started to leak (more). Quoting myself:

I feared my cleaning method removed important sealing areas, that are just sealing because they where clogged.
Definitively, kind of.

Always change your coolant!
 

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Likely the previous owner of the L27 didn't change the coolant. If that engine had the orange coolant, I believe it really destroyed the intake gaskets and promoted the pitting.
Are the camshaft lobes badly damaged?
 

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Over the span of MANY YEARS I've dealt with many pitted sealing areas. My fix was(assuming the pits are not very deep) using a HIGH TEMP SEALER made by ZEP. This stuff is the best for sealing up any surface. After it dries, it stays flexable and HEAT RESISTANT(great for sealing up header leaks or stock exhaust manifolds. This product is good for very hot temps (like header or exhaust manifold sealing surfaces). BEST STUFF EVER. We put some on my son's leaky pitted exhaust maniflods on an OLD DODGE mini motor home and it sealed up areas 100% I thought would not hold. But after several trips to the local drag strips towing his hot rod......NO LEAKS. It is more spendy than run of the mill sealers but 200% better. Heck, I've even used it to seal up rusty pitted exhaust flanges and pipes...... works every time but an over-nite curing time is necessary. exhaust manifold gaskets....... not even close to ZEPS results and longevity. If I remember correctly, it's good for 1200-1500 degrees and it stays flexable. We wouldn't be without it at our shop...... unless it becomes un available! Heaven forbid............... Jake
 
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