Firehawk068

I need to replace my Intake/Exhaust gasket this weekend, as the front part of it (exhaust port) is blown out. I have a nice exhaust leak because one of the POs put a couple regular washers instead of the proper spring washer on the top front bolt...............(I already got a couple new spring washers from the Jeep dealer)
Here's my situation.....
At some point in my '96 XJ's life, one of the POs installed a replacement engine.....
I don't know any of the details as to why it needed to be replaced. All I do know is that they did a crappy job when they did it.
Over the time that I have owned it, I've had to fix a number of issues like: Bolts that have been left loose, Brackets that were missing, Wiring that wasn't installed safely.........ETC.........ETC.
The 4.0 engine that they swapped in is a newer engine. I am not sure if it originally came from another XJ, or if it came from a Grand, or a Wrangler............I believe it is a 2001 engine (The barcode sticker on the front of the valve cover has a date of 10/00 on it).
When they swapped it in, they did not use the '01 intake manifold. They used the original '96 intake manifold on it.
What I have now, is an '01 engine/head with a '96 intake on it..........
My question would be "which intake/exhaust gasket do iI use?"
I have researched them, and the gasket for the '96 is different from the one for the '01............I bought them both just so I wouldn't have to run back to get another one while I have my XJ torn apart.......
I am sure once I get it apart, I could figure out which one would be a better fit, but does anyone have any experience with using an older intake on a newer head? (I know it's counter-productive, and usually people do the intake swap the other way around, but this is what I am stuck with for the time being)
Is there anyone else running a newer 4.0 with their older hardware that has done an engine swap?
All opinions are welcome (and I already know, I should just get a '99-'01 intake and be done with it!)

Bustedback

When I swapped a 99+ intake on my 95 I used the 95 gasket, no issues. Since you have both styles, compare the bad one to the new gaskets and use the one that is different. The old one may have burnt out because it was wrong or not torqued properly. Good luck.

belvedere

Since you mentioned incorrect washers, shoddy work by PO, etc, I thought of a write-up I had read on here once about selecting replacement manifold hardware. It was a good read, and looked like the author had done his research. Problem is, I can't find it on the site, and don't remember who wrote it (5-90, maybe?). Does anyone else remember this and know where to find it?

SeriousOffroad

You can ID the block and the the cylinder head by Googling the casting numbers.

5-90

If it cited experimental results WRT strength retention vice heat cycling, that would have been me. I've been using copper alloys on exhaust for years - typically half hard marine brass (70/30) undercar, and Si-bronze or Al-bronze for manifold screws.

The washers may be replaced with standard Belleville spring washers - which will probably work better (I've explained the whys & wherefores of that as well.)

And, before you put the new gasket in place, give it a light, even coating of "Sensor Safe" copper-bearing RTV first (I won't use anything but Permatex/LocTite.) It won't go amiss, helps stick the thing in place, helps it seal, and helps keep it from burning through if you get an exhaust leak starting somewhere.

Retorque your manifold screws annually, paying particular attention to the lower back screws (they usually loosen first.) There is ONE formula of threadlocker that will be useful here - I believe it's LocTite #277, or equivalent. Anything else? Don't bother.

New studs may be cut from 3/8"-16 threaded rod, or generic hardware store parts may be used. Go with brass-on-steel again, since you'll have to replace nuts anyhow (the OEM studs are usually 3/8"-16 on the "head" end, and 3/8"-24 on the "nut" end. There are sound engineering reasons for doing so, but they don't really apply here. However, studs should be retained at each and, and optionally on the top centre, so you don't have to wrestle the parts as much to get them in place!)

I've covered this pretty extensively on the board here, so a search should prove fruitful. It's a simple job, as long as you keep your head screwed on right.

MonacaYankee

Whenever I bought a 99 replacement gasket the holes were to small and it did not cover everything quite right on my 99. I had the store pull me one for a 98 and it was exactly right. Weird.

5-90

If it was for the 0331 head, that's because the exhaust ports are smaller than those for the 0630. This was done to "improve catalyst light-off times" with the head revision.

cruiser54

How about doing ^^ this?

Block casting and head casting numbers. Head casting is really the most important one to get.

That way, we would know for sure what we're dealing with.

Firehawk068

I found out a few things about my engine in the process............

Here's the two different gaskets I bought.
The top one is listed as replacement for '99-'06 (MS93094)
The bottom one is listed for '91-'98 (MS94790)


I'm not sure I had any intake leaks, but I'm guessing so...........The #1 and #2 exhaust ports were blown out on the side and underneath. The #3 and #4 exhaust ports were blown into each other, and out the top.........
I also found a few loose(finger loose) bolts under the intake manifold....


Once I got the manifolds off, it was obvious which one was the correct one.........The 99-up gasket exhaust ports were too small, and covered up part of my exhaust ports......
So I used the one for '91-'98


This told me that there was no way that this was an '01 engine, like I had previously thought........
So in the process I checked all the casting numbers.
Engine casting number is 53020569, which research says is from '96-'98

Cylinder head casting # is 0630, which also should be from '96-'98


I'm not really sure if I am reading the date castings correctly, as I didn't really find much info when I tried to google it.
The block date casting is possibly (Day shift, at approx 12:30pm, on April 4th 1997)?


There was also this number engraved onto a pad on the other side of the block VL567555. I'm not sure what this may be either? possibly a build number?


The cylinder head date casting is only 3 digits......a DO8, or D08........so possibly some time in 1998?

The intake manifold casting #63010236 has a 1996 date casting on it, so it is probably original to the XJ........It cleaned up nice with a pressure-washer..........


So now I believe I probably have a 1998 engine in my 1996 XJ..........

One other thing that I had to fix was the nylon fuel line that runs from the steel line under the intake, up to the fuel rail. I barely put any force on it while trying to take apart the quick-disconnect and it broke!


I used a piece of 1/4" High-pressure fuel injection hose to replace the nylon piece.

I also cleaned the fuel rail, and replaced all the injector o-rings while I had it apart............


Next it was on to the Oxygen sensor..........The one I took out was the original one, with 170,000 miles on it..........NTK #56027916
I replaced it with a Bosch aftermarket replacement.



All put back together!


Now that my exhaust leak is fixed, and my O2 sensor is new, I am hoping my fuel mileage will improve..............It also threw a code last time I went wheeling (P0171-System too lean), so it was causing it to dump too much fuel..............

cruiser54

Thanks for the update.