[JHZR2]

Can anyone tell how well the underhood seal is supposed to fit?

My 266k mile ‘96 didn’t have a seal when I bought it. I’m not near my 445k mile ‘96 to check. But I know that I don’t get any fumes on that one.

I just got my hands on a “good used” seal, but it doesn’t quite make the width, see here:

about 1/2” on each side. It definitely helps reduce the fumes in the cabin when stopped with HVAC on.

I do have a manifold issue. The gasket most forward looks replaced/newer than the others, but still “old”, and it is subject to manifold expansion issues.

Furthest forward and most rearward look like this:

The center more cylinders show some mismatch too.

I love old diesels but don’t want to be breathing fumes unnecessarily. I have one or two old MB diesels that I’m also experiencing this with, I think from the manifold to turbo gasket. But those cars also have a two piece manifold with a flex tube partway, I suspect to help deal with different rates of expansion.

Any recommendations on where to start? Should I just remove the whole manifold? Should I replace it?

I may do a preeemptive head gasket so prepping now is the best bet.

Thanks!!

 

[YogiBayer]

There are 2 additional seals on each end of the hood seal I dont see.

 

[JHZR2]

There are 2 additional seals on each end of the hood seal I dont see.

You mean the foam pieces that are at both ends? They’re there. Just didn’t make the photo. They are hard, probably worth replacing with … ???

 

[Marq92]

I don't think the hood seal will affect cab ventilation. It seems like it is mainly for making sure airflow is directed below the firewall and not pushing up the back of the hood as well as keeping the elements from creeping in from above. Check your firewall grommet near the steering column and the others. Those would let fumes right in.

 

[JHZR2]

I don't think the hood seal will affect cab ventilation. It seems like it is mainly for making sure airflow is directed below the firewall and not pushing up the back of the hood as well as keeping the elements from creeping in from above. Check your firewall grommet near the steering column and the others. Those would let fumes right in.

Will do. It is markedly improved now that I put that gasket on.

 

[YogiBayer]

Try maritime foam stick on seals at Lowes

 

[M37]

IF your exh manifold is leaking, you should see a black soot pattern by the leak. I had the same issue, it was a clogged CAT and a few leaking exh manifold gaskets.

If your exh manifold is not leaking, check for excessive crankcase psi (blow by) or maybe a missing draft tube (the large tube that hangs down by the starter.)

 

[bigfish95971]

That is the normal molding.