Valve Head Recommendations?

[zenophryk]

Short question, can anyone recommend a good machine shop in the nashua NH area to refurb the head on my 2.5l TJ. Just got done pulling it off and now I need it checked out and such.

here's the back story.

So my TJ has had a strange engine issue for a long time now. while accellerating under any kind of load (uphill for example) as soon as the RPM reaches 2000 the engine feels like it wants to stall, or like it's running on 2 cylinders (it's a 2.5l). It bucks and generally runs like crap. as soon as it hits 2100 rpm, it's like a switch flips and all works fine. it's done this for years, through many tuneups and other part replacements.
Other thing, in the last 5 years I've had the exhaust manifold gasket replaced 2 times, and it developed a leak again about a year ago. been driving it anyways, it's a bit loud, but whatever. well when it was time for a sticker I parked it in my parking lot in Nashua and started driving my truck till i had time to work on it.

also recently it had started making a clicking sound for a while when starting it in the morning. the repitition rate sounded a lot like a valve issue.

I did a compression test and found cylinder 2 was at about 105 psi and the rest were around 125 - 130 (if I remember. I do remember the second cylinder from the front was considerable lower than the rest, and that plug had a whole lot more residue than the rest.
while taking off the head I noticed that one bolt (I think the FSM says it should be a stud, lower rightmost bolt) was missing, and another one, (lower 2nd right most bolt, so next to the one that was missing) was broken off, with nothing protruding outside the head. well, with as many times as the manifold gasket has been replaced, you'de think someone would have mentioned this. guess not.

So I decided it was time for a valve job, why not. the head has 150k on it. maybe this will take care of some issues.

Anyone have any other thoughts? other good things to do while the heads off?

-Chris

[johnsxj]

Since you have the head off, a couple quick checks you can do at home.....

Use a straight edge and feeler gauges to check if the head is warped (FSM should have specs on that)

Rest the head upside down on a couple of blocks of wood so that the combustion chambers are pointing up and level. With the spark plugs snug in their holes, fill the combustion chambers with gasoline, wait several minutes, then look to see what the level the gas is in the chambers. Look into the ports on the head to see which (if any) valves are leaking.

I'm going to assume the missing bolts/studs you are talking about are for the manifolds? The two furthest outboard should both be studs. The rest are bolts with large cone shaped washers.

The RPM specific rough running sounds just like the problem I had a few years back during the Moab trip. At a certain RPM and vacuum level (load) it would miss fire and buck, lower/higher RPMs/loads and all was fine and some cold mornings it would be a PITA to start. Turned out to be a weak ignition coil!!!!!!!

[zenophryk]

Thanks for the suggestions.
I did check the head for warpage, and it was ok. I will try the gasoline test, that should be interesting.

Yes, the missing bolt/studs are for the manifolds. last 2 on the bottom row. the last one was just missing, the one next to it is snapped off. Any reason to put studs back in, or can I just replace them with new bolts?

So for the RPM specific issue I have tried a bunch of different things, one of wich was a new coil about 6 months ago, which didn't help. I think the next step might be to take a hard look at the vacuum system and see if somethings wrong there. I think I need to understand that system a little better first though.

[johnsxj]

It's best to use studs on the ends (couple bucks at any decent hardware store). The snapped bolt can be removed by whichever machine shop you have do a valve job or you can drill it and use an easy out at home.

[ZAEDOCK]

John pretty much covered it. Jeep 2.5L's are typically very tough and reliable (the main reason I don't install a V8 or 6). I haven't lived in Nashua in a long time, but a quick search found the following shops:

A H Machining, Inc. 205 W Hollis Street Nashua NH (603) 595-2878
Ab-Cim 99 Pine Street Ext Nashua NH (603) 594-4071
Accurate Centerless Grinding 17 Airport Road Frnt Nashua NH (603) 883-3747
CRW Company 35 Progress Avenue Nashua NH (603) 598-1977
Collins Precision Machining 55 Lake Street Nashua NH (603) 882-2474
D & S Machining 16 Airport Road Nashua NH (603) 880-6807
Datec Tool & Machine 50 Bridge Street Nashua NH (603) 598-6645
Gate City Ind Supply Company 50 Bridge Street Nashua NH (603) 883-3321
Highland Tool Company 20 Simon Street Nashua NH (603) 882-6907
K 6 Manufacturing 15 Macdonald Drive Nashua NH (603) 888-4669
Kendra Corp. 28 Charron Street Nashua NH (603) 883-1898
M & B Machining & Welding Company 11 Spalding Avenue Nashua NH (603) 882-4327
Mechanical Design & Machining 5 Kessler Farm Drive # 135 Nashua NH (603) 883-1831
Mija Precision, Inc. 460 Amherst Street Nashua NH (603) 880-4110
Nashua Industrial Machine Corp. 1 Pine Street Ext Nashua NH (603) 882-8174
Nim-Cor, Inc. 575 Amherst Street Nashua NH (603) 889-2153
P & D Machine, Inc. 29 Mason Street Nashua NH (603) 883-1814
Pell Engineering & Manufacturing, Inc. 29 Industrial Park Drive Nashua NH (603) 598-6855
Perpetual Machine Pine Street Ext Nashua NH (603) 595-3374
Phoenix Manufacturing 20 Simon Street Nashua NH (603) 880-3375
Precision Model Fab, Inc. 17 Airport Road Nashua NH (603) 883-6680
R & S Industries 51 Lake Street Nashua NH (603) 883-6710
Rapid Finishing Corp. 43 Simon Street Nashua NH (603) 889-4234
Reclaim Technology, Inc. 48 Bridge Street Nashua NH (603) 883-0401
Rethz Light Metal, Inc. 12 John Street Nashua NH (603) 880-8275
Silva Metal Machine 2 Townsend West #8 Nashua NH 03063 (603) 809-4154 F: (603) 809-4156 Map
Silva Metal Machine 2 Townsend West #8 Nashua NH 03063 P: 603 809-4154 F: 603 809-4156
Spray-Tek 25 Progress Avenue Nashua NH (603) 883-8014
Star Machine Company 17 Airport Road Nashua NH (603) 882-1423
Three D Machining Service 51 Lake Street Nashua NH (603) 880-0554

[Frank]

Holey Smokes ! That many in one town, they must all be related . FjR68

[ZAEDOCK]

When my wife graduated from Nashua HS, there were 1200+ kids in her class. We didn't have that many people in the town I grew up in.

[zenophryk]

So I got back from my vacation and did the gas leak test John suggested. The #2 location drained in about a minute, the others in about 4-5.

I also did a google search for machine shops, but not many will work on valve heads. That's why I was looking for a anyone who had experience with one in the area. I ended up going to lawrence crankshaft in Haverhill (I live in haverhill, but my tools are in Nashua.) I dropped it off tuesday, They said it should be done by the end of today.

This TJ will be ready for the trail by next year, one way or another.

On the Nashua school subject. They now have 2 High Schools North and South (they are only about a half mile from each other). Each one's graduating class is bigger than the total population of my high school. I actually bet the number of kids that drop out/don't graduate each year is still probably bigger than my graduating class.

Zenophryk

[ZAEDOCK]

Lapping the valves can also be done on a budget to help an old head seal better. Number and remove the valves, clean them and the head, and then with a lapping compound and tool, spin the vavle in it's seat with your hands. The valve will come out mint.

[zenophryk]

So I picked up the rebuilt head yesterday. Started putting it back on today. When I opened my box of new head bolts there were 6 bolts and 4 studs. not really studs, but the stud like bolts. What came off was 5 bolts and 5 studs. the studs are about 3/4 inch longer than the bolts. So thinking maybe they were miss packaged, I looked online and they show 6 and 4 not 5 and 5. Am I missing something? the 6th bolt is too short to go on the drivers side of the head.

[nostaw]

Arghh... Been off the board for a while... I would have suggested you call Bell Auto in Nashua and ask for for Bucky (one of the mechanics). Their mechanics are old school do a lot of resto work on the side... I'm sure he'd know a good machine shop for the valve job. Sounds like you've already sorted it out.

JW