First time tearing in to the engine - TDC - JeepForum.com

 
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post #1 of 8 Old 02-19-2009, 11:05 AM Thread Starter
meBrian
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1992 YJ Wrangler 
 
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First time tearing in to the engine - TDC

Ok. I admit I' had never done much mechanically till I got this Jeep. I decided that it was time to learn and do things myself rather than paying someone else.

I changed the oil for the first time and since did a brake job, changed the thermostat, installed a 3.5" lift, ignition switch, ECM replacement and a couple other things and nothing has fallen off or apart yet.

So, my engine took a dump yesterday and needs help, bad. It appears to be a head gasket issue as there is obviously water in the oil which blew into my airbox and made a nice puddle under the jeep.

Staying true to my goal of doing things myself, I am going to attempt this one on my own, but have a question.

I've heard from several people stressing out about Top Dead Center.

I only plan on pulling the cyclinder head and replacing the gasket, although I will swap out my water pump and Thermostat while I'm there.

Do I need to mess with getting TDC and if so, at what point?
Guys that were quick to give advice said be sure to get the TDC right, so someone please fill me in.

Thanks.


92 , 2.5 (Reman), AX5 (Reman), 3.5" BDS, 1" shackles, 33x12.50 BFG Muds on Black Crager 15x10s. 8.8 & D30 w/ TJ axle mod. 4.88, Metalcloak fenders and rails. Corbeau Seats and harness, Sirius Sat Radio

It's hip to be square!
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post #2 of 8 Old 02-19-2009, 01:23 PM
EABiker
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You will need the #1 piston to be at TDC whenever you change the mechanical timing components of an engine, (timing chain, distributer, cam..). If you didn't mess with any of that stuff, you do not have to worry about it!
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post #3 of 8 Old 02-19-2009, 01:35 PM
jbolty
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What he said ^^^^.

Most important thing is to follow the torque specs and the pattern. For both the head bolts and the manifold.

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post #4 of 8 Old 02-19-2009, 01:58 PM
Burnerman
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TDC is when the #1 cylinder piston is at the top of the compression stroke and both valves are closed. It just makes timing the engine easier as long as nobody rotates the crank when the timing chain or distributor is out. You really won't need to worry about it if your just pulling the head. You may wanna have the head checked for cracks or warpage by a shop. It would suck to put it all together and have it still leak..

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post #5 of 8 Old 02-19-2009, 03:32 PM Thread Starter
meBrian
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Do I need to pull the rocker arms before taking it to a shop?

Also, is there any reason to dig deeper if I had coolant in the oil?

I have pulled the head, and the gasket doesn't look bad. I thought the problem would be visible looking at the gasket, but it's not.

Is there another route that I need to check?

92 , 2.5 (Reman), AX5 (Reman), 3.5" BDS, 1" shackles, 33x12.50 BFG Muds on Black Crager 15x10s. 8.8 & D30 w/ TJ axle mod. 4.88, Metalcloak fenders and rails. Corbeau Seats and harness, Sirius Sat Radio

It's hip to be square!
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post #6 of 8 Old 02-19-2009, 04:03 PM
Jeepsr4me19
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You have far more to worry about than TDC. Getting TDC with head off is easy. You can watch the #1 piston and see it come all the way to top. The cam will need to be indexed to the correct spot but that easy also. can be don on a bench. If you got a high mileage motor, it may be time to rering it and put new bearings in as well as gaskets. I have pulled apart more than a 100 engines and put them back together so If you run into a issue post up. I am more than glad to help.
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post #7 of 8 Old 02-19-2009, 04:03 PM
jbolty
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If you take off the rockers, mark where they came from. The shop may or may not want them off, depending on what they are doing

The leak does no have to be obvious, there is a lot of heat and pressue at work. Too late now but you should have done a compression test. You may have a cracked block, as a worst case.

.
"The right to be heard does not necessarily include the right to be taken seriously." —Hubert Humphrey
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post #8 of 8 Old 02-19-2009, 04:04 PM
Jeepsr4me19
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Look at the top of the pistons. Is any of them Cleaner than the rest? Take a few pics and post up.
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