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-   -   ZJ Engine Refreshment (http://www.jeepforum.com/forum/f13/zj-engine-refreshment-1790025/)

ashland82391 11-14-2013 08:57 AM

Here's my clean 1995 GC limited 4.0 2wd with 270,000 miles.

http://i1070.photobucket.com/albums/...psc2b65e7e.jpg

http://i1070.photobucket.com/albums/...psd2f38b8d.jpg

In about a month I'm driving her from Michigan to Arizona while flat towing my YJ most of the way. I'll be the first to admit that's a pretty tall order for the 4.0 so I'm going to increase the odds of a successful trip.

First step was to test the compression. No point in putting money into a bad engine.

http://i1070.photobucket.com/albums/...ps1df5a860.jpg

http://i1070.photobucket.com/albums/...pse6d36b2f.jpg

Considering how many miles, the engine tested pretty good.

Dry 110 100 100 95 100 100
Wet 140 120 125 125 140 140

I think cylinders 2,3,4 tested lower because of the head gasket leak.

The zj is in great condition all around with only a few concerns.

Tasks

Replace Head gasket
Replace Oil pump

http://i1070.photobucket.com/albums/...ps96403800.jpg

While doing that I plan on replacing t stat, valve cover gasket, manifold gasket, injector o rings, and clean the rear diff. Everything else, plugs, wires, cap, rotor, water pump, trans, are all new or in good shape.

On to the fun! Tore everything apart. Head studs where kind of rusty so I let them sit in PB for a few hours. Last thing I need is for bolt to break of in the block.

http://i1070.photobucket.com/albums/...ps9a4b7d6f.jpg

http://i1070.photobucket.com/albums/...psfaa6fbc5.jpg

After a few hours, head bolts came out fine :-)

http://i1070.photobucket.com/albums/...pscbc10152.jpg

http://i1070.photobucket.com/albums/...ps16d79647.jpg

ashland82391 11-14-2013 09:01 AM

Just took the head to get cleaned and milled. Should be done on Monday :-)

WJ4x4LIFE 11-14-2013 09:10 AM

A couple of questions out the gate.

1.) What did you pay for it?
2.) Why a 4.0L, not a V8? two-part question, was is a kinda of first come first serve (with known HG issue) or a preference?
3.) Why a 2wd model, again preference or reason?

Sorry, to bomb you with ?'s, but I like some context background to enjoy the story and build! I wish you the best of luck in your trip! :D

ashland82391 11-14-2013 09:14 AM

Quote:

Originally Posted by WJ4x4LIFE (Post 17696441)
A couple of questions out the gate.

1.) What did you pay for it?
2.) Why a 4.0L, not a V8? two-part question, was is a kinda of first come first serve (with known HG issue) or a preference?
3.) Why a 2wd model, again preference or reason?

Sorry, to bomb you with ?'s, but I like some context background to enjoy the story and build! I wish you the best of luck in your trip! :D

It's not a new to me Jeep. I've had it for around 4 years and had been in the family it's whole life spending most of it in California and Arizona. I received it for free so I didn't complain about it not bring 4wd. Plus, the YJ is more enjoyable offroading.

xcaliber81 11-14-2013 10:07 AM

How did you do the compression test? I did one but after I was told I did it wrong.

ashland82391 11-14-2013 10:19 AM

Quote:

Originally Posted by xcaliber81 (Post 17697729)
How did you do the compression test? I did one but after I was told I did it wrong.

It pretty simple.

1.Disconnect ignition

2.Remove spark plugs one at a time whole testing each cylinder with the compression gage

3.Screw gage inlet into the spark plug port.

4.turn the engine over a few times. The gage should make 4-6 big jumps and then slow down dramatically. Stop when this happens. This will be you dry test number.

5.Then remove gage and poor in a small amount of oil into the cylinder. Just enough to coat the cylinder head.

6.Repeat step four on the same cylinder. This well be your wet test.

7. Do this to all 6 cylinders resulting in 12 numbers. All dry numbers should be similar and all wet numbers should be similar.

ashland82391 11-14-2013 10:21 AM

Quote:

Originally Posted by ashland82391 (Post 17698065)

It pretty simple.

1.Disconnect ignition

2.Remove spark plugs one at a time whole testing each cylinder with the compression gage

3.Screw gage inlet into the spark plug port.

4.turn the engine over a few times. The gage should make 4-6 big jumps and then slow down dramatically. Stop when this happens. This will be you dry test number.

5.Then remove gage and poor in a small amount of oil into the cylinder. Just enough to coat the cylinder head.

6.Repeat step four on the same cylinder. This well be your wet test.

7. Do this to all 6 cylinders resulting in 12 numbers. All dry numbers should be similar and all wet numbers should be similar.

Here's a good video that will better help you.

https://www.youtube.com/watch?v=X_tb...e_gdata_player

xcaliber81 11-14-2013 10:27 AM

i did not remove my spark plugs nor did i disable the ignition which resulted in 60 psi per cylinder. I also did that when i first bought it and i doubt my jeep has a 60 psi per cylinder engine lol.

ashland82391 11-14-2013 10:32 AM

Quote:

Originally Posted by xcaliber81 (Post 17698473)
i did not remove my spark plugs nor did i disable the ignition which resulted in 60 psi per cylinder. I also did that when i first bought it and i doubt my jeep has a 60 psi per cylinder engine lol.

?? How in the world did you test it with the spark plug in lol. Yeah, 60 is a pretty much shot engine.

xcaliber81 11-14-2013 10:36 AM

took out 1 plug at a time and started the engine ran for 5 or so seconds. everywhere else i have been reading said to remove all plugs and wires disable the fuel and ignition and crank for 5 seconds, so pretty much what you said.

ashland82391 11-14-2013 10:44 AM

Quote:

Originally Posted by xcaliber81 (Post 17698849)
took out 1 plug at a time and started the engine ran for 5 or so seconds. everywhere else i have been reading said to remove all plugs and wires disable the fuel and ignition and crank for 5 seconds, so pretty much what you said.

Yeah, your not suppose to actually start the vehicle lol. Ya live a ya learn. You don't have to remove all the plugs at once though. Just pop off the write off the end of the plug then remove the plug and remove the center wire from the distributer cap. It connect to the the ignition.

JohnCrabtree 11-14-2013 02:40 PM

You're actually supposed to remove all plugs at once. If you have a leak in between cylinders and you crank it, your engine will pressurize both cylinders and read as pressurized. If you take all plugs out and have a leak between 2 cylinders then it will not hold pressure at all.

You can get a false positive by leaving plugs in. In other words, it can read good when it's bad.

ashland82391 11-15-2013 04:20 AM

Pulled the oil pan. Way more difficult on a stock vehicle as oppose to a lifted one lol.

http://i1070.photobucket.com/albums/...ps265480e6.jpg

Oil oil pump vs new

http://i1070.photobucket.com/albums/...ps6b56082e.jpg

I also decided to do the rear main while I'm in there. I've heard how hard it is and how big a pain it it's to change but seriously it was cake...

http://i1070.photobucket.com/albums/...ps57cd3872.jpg

xcaliber81 11-15-2013 10:43 AM

its only a PITA if you tear it a bit and have to do it all over again.

WJ4x4LIFE 11-15-2013 12:21 PM

Quote:

Originally Posted by ashland82391 (Post 17696537)
It's not a new to me Jeep. I've had it for around 4 years and had been in the family it's whole life spending most of it in California and Arizona. I received it for free so I didn't complain about it not bring 4wd. Plus, the YJ is more enjoyable offroading.

Can't beat "FREE/given! :thumbsup:"


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