Are Renix XJs prone to exhaust manifold cracks

[Steev]

Most things I read about exhaust leaks are the 91-99 manifold.. the 87-90 is different..

Does it crack the same as the 91+ ones?

[jeep-man-man]

They all crack...

[5-90]

I'd imagine that they do, but I'm still waiting for mine to crack...

1987 w/260Kmiles
1988 w/255Kmiles
1989 w/170Kmiles
1989 w/150Kmiles...

5-90

[dfreeman616]

the 89 i pulled with over 200k had no crack. i'm not sure about the 87 i'm driving right now, haven't looked close and don't care, since i have nothing past the cat right now.

[MaXJohnson]

my '90 had multiple cracks at ~150K miles. I welded the cracks at 180k and the welds are still holding up 75k miles and counting.

[falcon1235]

my 89 has 220k on th ticker and no cracks...... however my 93 has 150k and was cracked to the tune of about 1/4 inch wide 2 inches long in the last y be for the collector

[dizzymac]

89 & 90 XJ's.....170k...no cracks here.

[Saudade]

'88, no crack.

[muddshutter]

88 no crack, although i think it uses crank at night when i am not looking?

[Rob Mayercik]

Possibly the biggest contributor to cracked manifolds is "dead" engine mounts, which allow the engine to move enough under throttle to cause the manifold to crack (not much play in the exhaust system).

If yours is not cracked, take a good look at your motor mounts. If they're shot, change them out before they do you in.

Rob

[SuperRA]

Possibly the biggest contributor to cracked manifolds is "dead" engine mounts, which allow the engine to move enough under throttle to cause the manifold to crack (not much play in the exhaust system).

If yours is not cracked, take a good look at your motor mounts. If they're shot, change them out before they do you in.

Rob

Ah, this is good to know, I didn't even think of that. I just replaced the motor mounts and also I'm going to add a flexable joint to the exhaust system which should help.

I'm at about 180K, no crack here...

[martin]

I have a 88 XJ, 158K and no cracks in the manifold. I asked the dealer mechanic who works on my XJ, he in his late 50s and worked on XJs when they were made by AMC. I asked him about manifold cracks, he told me it the 91 and later ones that crack.

Remember the Renix engines have a EGR valve while the '91 and later do not. The EGR tube from the exhaust to the valve supports some of the weight so the manifold. That may contribute to the lack of cracks in renix manifolds.

[XJING]

My '88 cracked at around 180,000 by way of loose motor mounts.

[j99xj]

They all crack...

Sounds about right. I put some muffler patch on mine and its still holding up. Runs a little better too now that the O2 sensor isn't getting a false reading.

[Lodi Jim]

88 with 281k and no cracks, but am tightening manifold tightening nuts yearly. Running good motor mounts, that is good info.