Anyone here run without the heatshield over the manifolds?

B

Biernuts

NAXJA Forum User

Location

Coeur d'Alene, Idaho

• Sep 28, 2005

• #1

89 XJ 4.0 5sp

I replaced my exhaust system from the block back and I want to be able to check the manifold bolts every so often to make sure they are properly torqued.

I know that the engineers would not have designed the shield if the engine didn't need it but it would sure be easier to check the bolts without the heatshield there...

I have new O rings so no leaks to start a fire...

 

afd516

NAXJA Forum User

Location

Fort Worth, Tx

• Sep 28, 2005

• #2

I don't run one for the same reason. I have had no issues.

 

old_man

NAXJA Forum User

Location

Loveland, Colorado

• Sep 28, 2005

• #3

There have actually been TSB's about adding more heat shields. You can end up with heat soak issues.

 

B

Biernuts

NAXJA Forum User

Location

Coeur d'Alene, Idaho

• Sep 28, 2005

• #4

old_man said:

There have actually been TSB's about adding more heat shields. You can end up with heat soak issues.

Click to expand...

Heatsoak as in long term damage to say, the injector harness, TB hose, etc? I thought MAYBE the heat might get bad enough to futz with the electronics up top...but not sure.

I suppose I ought to slap mine back on. I just have having to unlug the injectors everytime I torque my bolts...I can't see to get at them unless the heatshield is off. Maybe I just haven't done it enough times...

 

M

mattmankow

NAXJA Forum User

Location

Westminster, Md

• Sep 29, 2005

• #5

The tsb actually says that the heat coming up can cause the injectors to cause the engine to misfire.

 

old_man

NAXJA Forum User

Location

Loveland, Colorado

• Sep 29, 2005

• #6

Heatsoak, as in you turn off the motor, give it a few minutes, and it won't start or if it does, it runs like crap.

 

afd516

NAXJA Forum User

Location

Fort Worth, Tx

• Sep 29, 2005

• #7

Like I said I have not had any issues in regaurd to no heat shield.

My engine compartment is well ventilated though so the heat escapes easily.

Now, with that being said I would not argue with oldman and his knowlage of the xj. He knows what he is talking about.

 

8Mud

NAXJA Forum User

Location

Central Germany

• Sep 29, 2005

• #8

Re: Anyone here run without the heat shield over the manifolds?

I had the heat shield off of my 87 for about ten years, I never had any issues. I did have some trouble with the metal hardline part of the fuel line vapor locking though. It was a little too near the exhaust manifold. I rerouted it and the problem disappeared. I always thought the heat shield was more cosmetic than functional though, there are some pretty large gaps in it anyway.
Removing it made inspection of the exhaust manifold much easier and motor cleanup (baked on mud) much more thorough. But I can see where removing it, might heat up the middle injectors, right after shutdown.

 

B

Biernuts

NAXJA Forum User

Location

Coeur d'Alene, Idaho

• Sep 29, 2005

• #9

OK, I've heard enough...It's going back on.


Since I just put new O rings on the injectors, do I need to put new ones on again? How many times can I pull the injectors out before I compromise the O rings?

 

M

mattmankow

NAXJA Forum User

Location

Westminster, Md

• Sep 29, 2005

• #10

you should be able to unplug the injectors and slide the shield in without removing the injectors.