HI am going to tackle the Intake/Exhaust gasket this weekend on my 89 XJ 4.0. any tips on doing the job? Do any of the bolt holes go thru to coolant? do i have to drain down my anti freeze. i have a new exhaust manifold (stock replacement) with gasket. anything else should i get before the tare down? any help would be great.

 

No need to drain coolant. I recommend using a ratcheting 14mm wrench on the lower bolts. You should be able to access them all fairly easy from up top.

 

Well I started the job sooner than I thought and got it all apart. I have 2 questions.
1 there is a sensor on the left side of the block about 1/2 inch above the oil pan that is broken what is it?
2 there is a pipe going from the exhaust up to the bottom of the intake what is that called. t was able to remove it from the intake but I cant remove it from the exhaust.

 

It's the pipe for the EGR valve. That's how you get exhaust gas into your intake to make the federal government happy. Chrysler eliminated it on later XJs.

 

Knock sensor.

 

So making a block off plate and plugging the 2 holes shouldn't make any difference in running.
Also the 2 piece knock sensors I'm finding are replacement for the one piece knock sensors.

 

You want both the knock sensor and the coolant temp sensor working. Having the EGR tube hooked up will help anyone pass visual inspections or smog down the road, no harm in having it look normal. Mine seems to maybe have some blockage in the vacuum line to it's diaphragm..I should check that.

You might check your o2 sensor ground, 12v feed, 5v feed and it's wires while you are there. Engine mount also. Make sure your injector O rings go on and in OK. Lastly, often the MAP tube ends up broken or left off.

Fuel connects have two O rings with a spacer. Don't loose any spacers!

 

Awesome thanks for the info!


Another Question I want to replace all the manifold hardware because the bolts I removed are in very bad shape. what grade should I buy 8 or 5. I was told 5 is the better choice for this because it is closer to the original bolts. any truth in that or should I buy grade 8

 

5-90 had some extensive info on what is recommended. Unfortunately I don't have it. Myself, I'd just go with Grade 5.

 

Use Grade 5. The Grade 8 Bolts get brittle during the constant heating and cooling cycles.

 

Awesome thank you

 

On my 90 without ABS, I can get the rearmost, lower bolt with way long extensions and a universal, from above. If you have ABS it's next to imposable!

Takes some time and a few choice words, but you CAN get the rearward bolts underneath with the right extensions. I go over all about three times. Just good and firm.

5-90 found some brass, or bronze alloy that fit the bill nicely IIRC. Grade 5 will do fine though, I think.

 

Do you know what the torque specs for the bolts are?

 

I just go with tight, but, see the attached pic for sequence and torques recommended. If you already have it installed, maybe this will be helpful for someone that searches this thread.

 

Awesome thanks for all the info guys. I got the job done. its nice not hearing the ticking noise from the crack in the exhaust manifold. sounds like it did in 1989 when my dad bought it home from the dealer, Quiet!