The engine's a Mitsubishi 3.0L 12-valve, found in many Chrysler products. I haven't really checked the Montero for a few weeks and my father, who drives the vehicle, never bothers to pop open the hood.
Got a call from my dad this afternoon, saying the engine was running rough after he started it up. There was nothing wrong when he was heading to work this morning. He drove the truck all the way home, when I noticed the coolant temperature was at the 3/4 mark (I'm referring to the C as 1 and H as 4).
The coolant expansion tank was almost empty. I slightly turned the radiator cap to let off some pressure, then tightened it to prevent coolant spraying everywhere when it started to. I then filled the expansion tank and started the engine. The coolant temperature was now slightly below the half mark, which is normal.
I let the vehicle sit for about an hour, before opening the radiator cap again. It took about three quarters of a gallon before it was full. There's a coolant hose running to the throttle body which started to very briefly leak, and seeing I haven't been able to check everything for about a month, the coolant got a bit low. I had to order the part from the dealership, and it's going to be another 10 days before I get it.
Anyhow, after I refilled the coolant, I decided to slightly rev the engine to see if it would spray coolant out the radiator. It sucked the coolant back in, and the level started the raise when I let off the throttle linkage. There were some air bubbles in the radiator, which later went away. Took it for a drive, and apart from the fact that it runs rough (especially between 1,500-2,000 rpm), the coolant level stayed put.
At idle, it runs rough for a few seconds before idle speed dips below normal but it runs smooth. If you rev it up, it's a little rough up to 1,000 rpm then rough from 1,500-2,000 rpm. As you give it a bit of gas when it starts rolling, the engine vibrates bad enough to shake the entire vehicle.
I'm assuming the head gasket is good in this case, especially considering the engine started running rough when cold, before the overheating.
I then started pulling ignition cables off the distributor to see if maybe there's a plug that's not firing. The engine ran worse when any of the 6 cables were pulled off. Completely covered in sweat, and the exterior temperature showing 135 F, I decided to go back in. Just wondering what else I should look into when my brain cools back down. Thanks!
Got a call from my dad this afternoon, saying the engine was running rough after he started it up. There was nothing wrong when he was heading to work this morning. He drove the truck all the way home, when I noticed the coolant temperature was at the 3/4 mark (I'm referring to the C as 1 and H as 4).
The coolant expansion tank was almost empty. I slightly turned the radiator cap to let off some pressure, then tightened it to prevent coolant spraying everywhere when it started to. I then filled the expansion tank and started the engine. The coolant temperature was now slightly below the half mark, which is normal.
I let the vehicle sit for about an hour, before opening the radiator cap again. It took about three quarters of a gallon before it was full. There's a coolant hose running to the throttle body which started to very briefly leak, and seeing I haven't been able to check everything for about a month, the coolant got a bit low. I had to order the part from the dealership, and it's going to be another 10 days before I get it.
Anyhow, after I refilled the coolant, I decided to slightly rev the engine to see if it would spray coolant out the radiator. It sucked the coolant back in, and the level started the raise when I let off the throttle linkage. There were some air bubbles in the radiator, which later went away. Took it for a drive, and apart from the fact that it runs rough (especially between 1,500-2,000 rpm), the coolant level stayed put.
At idle, it runs rough for a few seconds before idle speed dips below normal but it runs smooth. If you rev it up, it's a little rough up to 1,000 rpm then rough from 1,500-2,000 rpm. As you give it a bit of gas when it starts rolling, the engine vibrates bad enough to shake the entire vehicle.
I'm assuming the head gasket is good in this case, especially considering the engine started running rough when cold, before the overheating.
I then started pulling ignition cables off the distributor to see if maybe there's a plug that's not firing. The engine ran worse when any of the 6 cables were pulled off. Completely covered in sweat, and the exterior temperature showing 135 F, I decided to go back in. Just wondering what else I should look into when my brain cools back down. Thanks!
