Deposits in intake runner, what is this?
Posted: December 23rd, 2015, 12:58 pm
Gents,
I've searched but I can't decide how best to phrase this to get a good result. I'm not exactly an experienced mechanic and learning as I go here. I dropped a fair amount of cash while I was deployed to have Russ Pottenger build me a stroker. It was then shipped to Tennessee where I had a shop install it in my '98 XJ. Now I've got hands on it, and have more than 3,000 miles on it. I've been chasing what I thought was an exhaust leak so I pulled the header and intake manifold to find that the fourth piston from the front has black deposits in the intake runner.
First, pistons 1-3 from front, which look fine: Second, piston 4: Should I be concerned about this? I also have what I think is a CCV issue that is coating the inside of my intake manifold with a fine coat of oil, trying to decide if that could cause something like this since #4 is closest to where the CCV enters the manifold as far as I can tell. I haven't pulled the plugs yet because I was racing a rainstorm to get the thing put back together. I'll be doing that shortly.
Specs, in case you need them:
Keith Black IC944 pistons for a 0.02 overbore (21cc dish)
12-wt crankshaft from a 258
Heat-treated Comp Cams 68-232-4
Stock style rocker arms
Comp Cams valve springs/keepers
Oversized intake valves (2.0 from 1.91)
Oversized exhaust valves (1.55 from 1.50)
Melling standard volume oil pump
Comp Cams two-row timing chain
Five-angle valve job, ported head, port-matched 99+ intake
24 lb/hr injectors from Five-o Motorsport
Thanks for any wisdom yall can provide.
I've searched but I can't decide how best to phrase this to get a good result. I'm not exactly an experienced mechanic and learning as I go here. I dropped a fair amount of cash while I was deployed to have Russ Pottenger build me a stroker. It was then shipped to Tennessee where I had a shop install it in my '98 XJ. Now I've got hands on it, and have more than 3,000 miles on it. I've been chasing what I thought was an exhaust leak so I pulled the header and intake manifold to find that the fourth piston from the front has black deposits in the intake runner.
First, pistons 1-3 from front, which look fine: Second, piston 4: Should I be concerned about this? I also have what I think is a CCV issue that is coating the inside of my intake manifold with a fine coat of oil, trying to decide if that could cause something like this since #4 is closest to where the CCV enters the manifold as far as I can tell. I haven't pulled the plugs yet because I was racing a rainstorm to get the thing put back together. I'll be doing that shortly.
Specs, in case you need them:
Keith Black IC944 pistons for a 0.02 overbore (21cc dish)
12-wt crankshaft from a 258
Heat-treated Comp Cams 68-232-4
Stock style rocker arms
Comp Cams valve springs/keepers
Oversized intake valves (2.0 from 1.91)
Oversized exhaust valves (1.55 from 1.50)
Melling standard volume oil pump
Comp Cams two-row timing chain
Five-angle valve job, ported head, port-matched 99+ intake
24 lb/hr injectors from Five-o Motorsport
Thanks for any wisdom yall can provide.