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Since I don't have the parts for my transmission yet, I'm going to replace some gaskets - specifically the valve cover and pushrod cover. I've got some leaks on this engine and I'd like to take care of them and get everything cleaned up.
When I pulled off the throttle body, I noticed an oil film on the gasket and gasket surfaces. Is this, and the carbon buildup, normal?
Other than around the butterfly valves on the throttle body, should I bother cleaning any of it up?
You could spray injector cleaner, let it take stuff off. CLean the gasket surfaces of course.
Throttle Body: spray with injector cleaner only, not carb cleaner. DO NOT scrub the throttle body bores, before or after the butterfly valve. Only wipe, as they have a Teflon coating already, and you do not want that taken off. There is actually a warning sticker on it. Why?
That carbon build up is more than likely due to a bad design. Yours is not bad at all. Part of the Idle Air Controller(IAC) can contribute to more or less carbon build up.
CLean your butterfly valves, no wire brushes needed.
I'm positive mine is worse than yours.
Originally Posted by adrianpglover
While I have these covers off, is there anything I should be inspecting or checking. Valve clearance or the like?
You can check the rockers, spin the push rods, etc. Pretty sure your engines clean and good to go.
Do not over tighten the valve covers, and make sure the valve cover surface is flat, and using the correct nut/washer.
When I pulled off the throttle body, I noticed an oil film on the gasket and gasket surfaces. Is this, and the carbon buildup, normal?
The throttle body gasket, with oil still on it.
Hardly any build up there to be concerned about.
But, the bottom of that gasket looks like it got HOT.
Was the coolant tubes running through the throttle body, engine overheated, and there was no coolant there?
Maybe thats what they look like after by bassing the coolant lines on the throttle body?
The carbon buildup is from the EGR gases combined with the PVC oil vapors.
If it was mine I would probably hit it with some oven cleaner inside the runners then the pressure washer just to get any loose material out of there so it doesn’t drop down into the engine. If you’re thinking of painting it, then you can hit the outside with the oven cleaner also. I’ve had good luck with using self etching primer and silver engine enamel.
Definitely want to clean the throttle board and butterfly’s as the can become sticky when closed.
On the side cover, I’ve had good luck with putting a small bead of RTV on the cover, install the gasket then a small bead of RTV on the gasket to seal to the block.
So all but 4 of the pushrods spin freely. The 4 that don't have the tappets lifted. I figure I'm not at tdc, probably on any cylinder.
No real evidence of oil getting past the valve cover gasket, but the pushrod cover definitely was leaking all around. Also, there's some sludge buildup on the non moving parts of the engine. I figure I'll run some seafoam through it at some point to tran and clean some of it up. I only run synthetic in my engines, but I'm the 8th owner of this one and I only picked it up 4 months ago.
Right now I'm soaking the pushrod cover in some simple green purple degreaser, along with the washers. Hopefully the rubber on the washers will separate more easily after this, but I'm not holding much hope for it. The pushrod cover gasket was pretty well gone, and the bolts didn't feel tight. I figure that's because the rubber had hardened along with the temperature cycling.
Since you are a synthetic oil guy, you can skip the Seafoam treatment.
Synthetic oils have a high detergent level to them they they will breakdown that that sludge at a slower rate so it will have less chance at plugging the oil pump suction screen vs the flush and dump with the Seafoam.
I bought a 90’s Camry the the previous owner went by the 10k miles oil change recommendation and it looked bad in the valve cover. I did an oil change with synthetic oil and did another 3k miles later and cut the oil filter open and was surprised on how much crud came loose.
I cleaned up the two covers, hit them with a pressure washer, then wire wheel, then 220 grit sand paper. Followed it up with a few coats each of high temp primer and some high tem grey paint, then put it all back together. Somehow during this I misplaced one nut, but my bin of nuts had a suitable replacement that I used for the engine grounding strap. Got everything torqued to spec, for the parts I could find specs for. Can't test run the engine since the transmission and starter aren't in place, but I'll do that later.
Thanks everyone for all of the help. I hope this clears up the driver's side oil leaks now.
