HT4100 4.1, 4.5, 4.9 Discussion, 86 seville 4.1 low engine power-issue in Cadillac Engine Technical Discussion; Ok, got an 86 seville with 57k miles. The car seems like it has a little low idle, will sometimes ...
Ok, got an 86 seville with 57k miles. The car seems like it has a little low idle, will sometimes go down to 475 in drive at a stoplight. I've noticed in the past 3 weeks with the A/C on and taking off from a stop, it bogs down, won't increase in rpm, and basically won't move out of it's own way(feels like its not getting fuel, but it is reading 12psi on fuel gauge when i hooked it up). I keep it floored and eventually it will start accelerating(5-7 seconds). It has stalled once i had to restart it. It also just seems low on power(i know these engines are underpowered to begin with, but this is excessive). It has a LITTLE rough idle, no antifreeze in oil, it doesn't sound like its missfiring either, no service codes, no motor noise or smoke either. Fuel filter has been changed and a tune-up done 12k miles ago. I'm stumped, ideas? camshaft?
It also seems boggy with the a/c off too, but it is worse with the ac on
Took it to a shop and got it fixed. The fuel pump was slightly weak and replaced. but the bigger issue was the timing was off by 20 degrees. I haven't touched the timing since I've owned it, bought it used 4 years ago. It now runs so much better, more responsive, no low idle, nothing, runs like a top!
Update. This fix by the shop was short lived. Within 3-4 weeks it was back to bogging down and lack of power. I had my friend who is a mechanic come over and look it again. We took it out for a spin and I hammered it, about 2 blocks away from my house at full throttle and 40mph it quit, and would only crank over. Turns out the cam gear sprocket was loose and came off and threw the timing chain off. We got a new timing set and water pump while we were at it too. I got the car back in late september and have been driving it daily since. runs great and idles where it should, it is really liking the cold nebraska january air. It must have been loose for a while would be my guess as it never really idled right since I've owned it. The original nylon gears were even in good shape on the old timing set. Weird, I've never heard of this issue on a 4100 before.
The "bottom of the timing cover" is the oil pan. The bolt HAD to go there. I wonder if he left it in there or extracted it. Probably won't hurt anything to sit down there. It's too large to get through the pump screen and too heavy to get end up above the oil pan baffles. It'll probably live at the bottom of the pan for the rest of the car's life, and no one will even know.
ok, got ahold of my friend that fixed it. he said that the bolt loosend up enought to allow the cam gear to come off the cam pin. the bolt was still in cam but it had backed it self up against the timing cover. it couldn't loosen up enought to fall completely out. damaged the timing cover and bolt head a little.