Changing head gasket, how difficult is it? (Engine is out)

Changing head gasket, how difficult is it? (Engine is out)

Postby Astro88 [OP] » May 17th 2010, 5:02pm

Hello.

I wonder how hard it is to change the head gaskets on my 88 astro 4,3?
I already have the engine out of the car.
I have never done this kind of a job, is it difficult?

Is there some guides i can find online?

Anything special I have to remember?
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby LEVE » May 17th 2010, 5:10pm

It's not hard... but it is time consuming. Just go slow, use a manual, be aware of your torque settings and buy a Head up kit for the gaskets and seals you'll need.

Whenever I pull a head here's what I do for every cylinder.

1. Rotate the piston to BDC (Bottom Dead Center).
2. Spray the cylinder walls with Carb Cleaner.
3. Use the air compressor to dry the walls.
4. Run my thumbnail up and down the walls searching for unseen grooves.
5. Recoat the cylinder wall with motor oil.
6. Rotate the Piston to TDC (Top Dead Center).
7. Flood the top of the piston with Carb Cleaner.
8. Wait about 15 seconds for the carb cleaner to soften any carbon build up.
9. Using scotchbrite or a thin putty knife, I remove the carbon.
10. Repeat step 7 - 8 as necessary.
11. When the top of the piston is clean I again flood the area with carb spray.
12. Dry the area off with the compressed air.
13. Again put some oil into the cylinder and lower the piston.
15. Move on to the next cylinder.
16. Put a rag into the cylinder just worked on to keep it clean.
17. Repeat for all cylinders.
19. Remove ALL head gasket debris.
20. Using scotchbrite I hunt for burrs on the block mating surface and remove them.
Last edited by LEVE on May 17th 2010, 5:18pm, edited 1 time in total.
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby Woodweasel » May 17th 2010, 5:11pm

Well if you pulled the engine, you can pull the heads. Get yourself a shop manual. They have a decent explanation along with some grainy black and white pictures, they do help to see what they are talking about sometimes. The hardest part is getting the wires and hoses back in the right spot, which is minimal. Removing the intake and heads is easy with it on an engine stand.

Tear into it!!!! :banana: You run into problems? bring em back here if you cant figure it out. Thats what its all about!

GOOD LUCK and keep us posted!
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby 1992RS » May 17th 2010, 5:13pm

man with the engine out this should be a super easy yet time consuming job, the worst part of changing the headgaskets in these vans is the limited work space and with the motor out you have essentially made this the easiest motor ever to work on. as far as a guide check out www.autozone.com you may have to complete a free registration but they have free repair manuals that include torque specs and tightening/ loosening sequences also, i used the site to get the info for my 1992 and it was very thorough.. hope this helps and have fun getting it done and remember to reward yourself a beer or something when your done for the night, also remember to get new head bolts as they are stretch type bolts and will require changing.
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby ShAgSTRO » May 17th 2010, 5:31pm

relatively easy...certainly easier than having the engine in
1986 Astro...I like my EFI carb ;)
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby Astro88 [OP] » May 17th 2010, 5:41pm

Thank you for quick replys.

I have one more question. I took of the rocker cover some days ago just to look inside. It seems like there is a bit of "hardend" (dont know the english word) oil inside.
What is the best way to remove/clean the head when its loose from the engine? I dont want to do anything wrong with the valve spings etc inside there.
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby 1992RS » May 17th 2010, 9:13pm

use a good aerosol degreaser and nylon brushes, thats what i did, also definately bring the heads into a machine shop and have them checked for cracks and warping hate to see you put it all back together and have it leak again in a few days
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby Astro88 [OP] » May 17th 2010, 9:17pm

Ok, but can clean it with water also?

The head gasket on the engine is not blown, but I want to change it because its fairly old and I have the engine out of the car.
So I guess there is no damage on the heads.
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby chevy57bert » May 17th 2010, 9:51pm

Astro88 wrote:Ok, but can clean it with water also?

The head gasket on the engine is not blown, but I want to change it because its fairly old and I have the engine out of the car.
So I guess there is no damage on the heads.


I use a hottank (@ work)
Why did you took your heads off Torje?
It seems that the gaskets look good.
maybe you have an other issue with your engine?
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby Astro88 [OP] » May 17th 2010, 10:00pm

I have bought a "new" engine, because the engine in my car is broken.
Before installing the new engin I thought it might be smart to change the head gasket so I dont have to do it in 6 months.
I guess the head gaskets on my engine is ok, but would not you change it now as the engine is out of the car?
I guess the head gaskets on this engine is fairly old.
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby chevy57bert » May 17th 2010, 10:13pm

Astro88 wrote:I have bought a "new" engine, because the engine in my car is broken.
Before installing the new engin I thought it might be smart to change the head gasket so I dont have to do it in 6 months.
I guess the head gaskets on my engine is ok, but would not you change it now as the engine is out of the car?
I guess the head gaskets on this engine is fairly old.


Didn`t know that.. Your the Man Torje. better to do now...
did you get in contact with Ice_driver??
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby Astro88 [OP] » May 17th 2010, 11:28pm

Ok. didn`t contact him, but got his e-mail
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Re: Changing head gasket, how difficult is it? (Engine is ou

Postby tedanderson » May 18th 2010, 2:12am

From my own experience, I would suggest that you get a breaker bar in addition to a torque wrench. Secondly get some new sockets and make sure that they are the 12-point type. If you cant afford a new set, at least get the exact size for the head bolts and intake manifold bolts. On most projects, if you have a metric bolt, you can usually get away with the standard equivalent and vice versa. However, the head bolts and intake bolts will not be as forgiving. It's been a while since I've done this type of job so I couldn't tell you the exact bolt size but take the extra time to make sure that the socket fits snugly and there isn't any wiggle room. And be sure to buy only Craftsman, Snap-On, or any other high-quality equivalent. The $5.99 socket set from your favorite discount store will leave you with plenty of heart-ache. Third, use SLOW and STEADY movement when breaking the bolts loose. Don't yank, jerk, or shove the breaker bar. Take your time with breaking the bolts loose. Lastly get a big piece of cardboard. A pizza box works well for this- When you start pulling out bolts and rods, poke holes in the cardboard in relation to where the parts go on the engine and then stick your rods and bolts into the holes and use a magic marker to make notes on the cardboard if needed. e.g. "This is the special screw that goes behind the throttle body..don't lose it"

But I would have to agree with what was said about it being out of the van- The job can't get any easier than that.. unless you put it on an engine stand. Then you won't have to bend over while you work.
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