Sometimes, what looks like a routine repair turns into something kind of… unexpected. That was the case with this Jeep Grand Cherokee SRT8, which came in showing signs of trouble: low coolant levels and noticeably poor performance. 

At first glance, there were no visible leaks, so we topped up the coolant and began our checks. That’s when things got interesting—rather than circulating properly, the system was boiling the coolant. Suspecting a circulation issue, not unheard of, we removed the thermostat to help it run cooler and allow us to bleed the cooling system effectively. 

With the system bled, we moved on to checking the thermofan operation. The fan worked as expected with the A/C on, so we ruled that out as we could prove operation. At this point, the Jeep was still running rough, with a clear misfire at idle and a check engine light on the dash. 

We moved on to head gasket testing by performing a hydrocarbons test in the cooling system, as overheating and poor running can often point in that direction. Fortunately, for us and the customer; the test came back clear. 

Still chasing the issue, we decided to replace the thermostat—our initial suspect. It helped slightly but didn’t resolve the rough running. That led us to the next concern: a misfire. On closer inspection, cylinder 8 was misfiring. We swapped coils and spark plugs around to see if the fault would follow, but it stubbornly stayed on cylinder 8. A compression test came back healthy, which meant we weren’t dealing with internal engine damage—always a relief. 

At this point, we turned to a smoke test to check for intake leaks. That’s when the real surprise hit us. We found smoke pouring from the intake manifold area—something clearly wasn’t right. Once we removed the manifold, we discovered the root of the problem: the manifold itself was melted. Yes, it actually melted. Watch our Video....

This kind of failure is incredibly rare—we’ve never seen it before, and even after asking around, it seems to be virtually unheard of. It’s not often that a plastic intake manifold fails so dramatically, but in this case, it was the missing piece of the puzzle – perhaps something engineers should have predicted? 

It’s not every day a Jeep throws us a curveball like this, but that’s what makes this job so interesting. Each vehicle has a story, and this SRT8 definitely gave us a memorable one to tell. 

Contact Rawson Motors for all your car servicing needs in Officer and surrounding suburbs. Our technicians won't stop till your issues are resolved.