falcon

I have a 1990 Jeep Cherokee i6 that I recently tuned up, and cleaned off the engine block. I noticed that there was a build up of oil on the engine and figured that there was a gasket leak. So I cleaned it up really well sprayed it down and discovered that my leak is from the bolt between the 3-4 cyl and it seams to be leaking coolant. I am planning on installing a new head gasket on it. I have rebuilt an old motorcycle and did a complete tear down and rebuild on it, and I also helped with an engine swap, so I am not to afraid to tackle this issue. It runs OK, a little rough even with a tune up, cleaned throttle body and ICM, cleaned the MAP sensor, and adjusted the TPS, installed new plugs, dist cap and rotor, fixed electrical issues, replaced the fuel pump, fuel filter and regulator, plug wires, but it starts right on up and doesn't overheat. It has a rough idle but sensors seem to be in spec and test ok. I do have some basic questions about replacing my head gasket, since I was quoted 1,500 for the replacement including valve seals and a machine surface of the head and up to 2,000 for a replacement head if it is cracked (new OE I suppose). It looks like I will be doing this myself since its otherwise a really slick Jeep and worth a new gasket.

1 Head bolt replacement.. It seems like new head bolts are required? I plan on doing this any way but are they necessary to replace the bolts? The manual was unclear about this.

2 Are cracked heads a common problem in this year/model? How likely would it be that it is cracked? I got fear mongered into believing that I may have a cracked head but it looks to be in decent shape. I guess I could pull it off and asses the damage to it, but the car hasn't overheated as far as I know. Should I worry about this?

3 Valve cover bolts. One is an odd non OE bolt, where can I order these I don't see them available anywhere?

4. Does the Head need to be resurfaced? My mechanic friend says that I should probably do that? If I need to maybe I can also have him swap the valve seals since I don't have the valve spring compression clamp and valve extractor tool for a car. Should I be concerned about it?

Sorry for the barrage of questions.

Thanks

Diesel

1. It is always a good idea to use new bolts, whether it be for corroding reasons or structural integrity.

2. Cracked heads are not common in the 1990 year, although anything is possible. Don't assume, wait til you get it off, inspect it, and go from there.

3. Take one to Napa and they can match it up for you.

4. It is by no means necessary and completely personal preference. I choose to do so.

denverd1

1. yep new bolts. heated bolts stretch over time and can lose proper torque
2. not sure
3. google
4. compression test before tear-down should tell you if its necessary or not.

I Leak Oil

1.most head bolts are designed to stretch, the HAVE to be replaced everytime. Otherwise you have very inconsistent torque on all bolts. And possibly snapping them.

2. Just like he said. Its not common on 90's

3. Same thing he said, napa know
how baby!!!!lol

4. Like the other poster said a compression test will tell you if its needed at all. But i have a question, why would you risk any further issues and having to tear the head back apart. Here at my shop, and on any head job i do at home. I always send the heads to the machine shop before putting it all back together

belvedere

When you remove the head, take it to a good machine shop. Tell them you want it pressure tested, magnafluxed, and checked to see if it's flat. You may also want to have them do a valve job.

I Leak Oil

Valve job is good idea whenever its in a machine shop. Back to 100 percent compression. Feels like a new motor most the time if they were a little leaky

denverd1

how many miles on her? I'd look at doing some other things to it while the head's at machine shop.

I Leak Oil

Like ls1 valves. Woot woot lol

car5car

1.Put head upside down and fill combustion chambers by ATF or diesel fuel to check valves.
2.I use 20" aluminum level from Home Depot to check warped heads.

3.Cracks are usually between valve holes, clean by drill wire brush to check for cracks.

falcon

Cool guys thanks

It's got 181,xxx miles on it with the original head gasket.

What else would you recommend doing? I recently did a compression test on it it was in spec seems to be in reasonable shape for its age.

Fund a machine shop to take care of my head and they said no sweat, that I would not need a new hed and they could do all of that stuff.

I feel better knowing about the head bolts, they didn't look reusable frothe last time we did valve work on my friends truck so I wanted to be sure that I should absolutely buy new bolts.

Only dreading getting those exhaust bolts undone ... Should be fun with out an impact driver. I could borrow one I suspect.

I Leak Oil

They aren't as bad as you think. Just tear it down to that point and you will be surprised. I did all mine no issues with a 1/2'' ratchet

DFlintstone

Take your sweet time on the manifold/head bolts. If you can get a drift, (old head bolt ect) on a tough one and smack it good, might help. Also going IN a smidgen will sometimes help free a tough one. Also getting them loose while it's warm/hot could help.

I recently broke one (easy front) manifold bolt and it took me a good while to drill and tap for a new one, and I'm no noob!

"1.Put head upside down and fill combustion chambers by ATF or diesel fuel to check valves.
2.I use 20" aluminum level from Home Depot to check warped heads."

Yep^. "shade tree", you then hook your valve to a drill with fuel line and apply grinding "lapping" compound until the seepage is slow and even. (head on it's side)(works!)

If the head is not flat, you chain it to the hitch, stand on it, and have your old lady pull you down a cement road made by men being paid by the hour. (untested)

I Leak Oil

Buahana. You sir, are a funny *** hole

DFlintstone

Didn't intent to come off as any sort of "hole"

DieselDaze

this can and only will work if the road is wet, gives it the wet sand effect that the head needs to obtain plane..