Exhaust Manifold Leak Fix On A Budget

[zero]

Just got done putting new valve seals in my 22RE in my 1988 Mini-Cruiser. That went fine. I found the all the exhaust cam-follower clearances way too tight. Had around .005" clearance on all when checked cold, yet the intakes were fine. I assume that is from valve-seat recession over the years. Amazing the valves did not start to burn out. They would of soon.

On to the next thing I wanted to fix. Exhaust manifold has been leaking since I got it. Makes that exhaust "ticking" sound whenever I'd push on the gas. I've ruined a few exhaust manifolds on some other rigs driving too long this way. Ate up the cylinder-head on my 318 V8 Champion Class A.

I've dreaded working on the Toyota due to the aluminum cylinder-head and the likely-hood of stripped threads in the head where the exhaust manifold studs go. With a rig this age -who knows who else did a bad job of installing thread inserts in the past.

I had parts ordered that our wonderful Postal Service lost. USPS tracking shows the package being in the same mail sorting facility for a week. I suspect the real name for that is "lost." I got fed up waiting and decided to fix with no new parts.

This Mini-Cruiser will not fit in my repair shop. Too high. So I had to move a lot of tools into my solar/farm-equipment shed and work on the Cruiser on there on the dirt floor.

I have an extra 22RE sitting in my barn from a 87 1 ton dually. I yanked the exhaust manifold off of that and the gasket still looked good and most studs and nuts came out OK. I pulled the manifold off the Mini-Cruiser and all went pretty well. Would of been REAL bad without torches. After heating all nuts - most came off without breaking or galling. They appear to be stainless-steel and two did gall. Three studs came out of the head. Two bolts broke no matter how much I heated them. One for the exhaust shield and one where the exhaust pipe bolts to the bottom of the manifold. Got the manifold off and found the gasket burnt off at #3 and #4. Manifold also looked warped there.

So - I decided to use the other manifold and used gasket. Cleaned up all the threads with some metric dies. Drilled out one broken stud for the heat shield. Also got the oxygen sensor out and it was pretty stuck. Good time to get it out and free, and then reinstall.

Put the manifold back on and added some 3000 F degree furnace cement to help the seal. I've used high-heat furnace cement before with problem exhaust leaks and it's worked well.

So all together with no new parts. I'd much rather have used a new gasket - but none were available locally and the ones I ordered seem lost by our bankrupt US Postal service. If I'd ordered one today from NAPA, I'd had it in two days and paid twice the price I gotten it on-line (if the mail hadn't lost it).

Got done and drove it 200 miles. So far, so good. No leaks. Sounds like a new engine -even though it has 145,000 miles on it. If that old gasket leaks - it will be easy to replace now since all the threads and nuts are clean and coated with ceramic Never-Seiz.

[Eve "n" Stephen]

I had the same basic job done recently. I have no place to do any major work on my 22r, so took it to a recommended shop in Klamath Falls, Lee's Automotive. They are very familiar with this engine, which was good. 3 studs broke getting the exhaust manifold off, but they did get them out without pulling the head. Once back together, it still leaked, so they had to pull it apart again, it was warped. Off to a machine shop, then back on and all was good. I felt that the $214 they charged was very reasonable.

Things are much quieter now! I can even hear a bit of valve clatter. I adjust them about every 12,000-15,000 miles. They were really tight when I bought it 3 years ago, a wonder there were no burned valves.

Steve

[WME]

The joint I had the most problem with was the 4 into 2, manifold to down pipe. Finally after replacing 3 of them I found the secret. Loosen the manifold and then torque the down tube joint carefully so that you have an even crush on the donut gaskets. Then tighten the manifold.

I probably screwed the local parts store inventory buying 3 gaskets set in about 4 months exhaust gaskets sets.

[zero]

. They were really tight when I bought it 3 years ago, a wonder there were no burned valves.

Steve

Yes - I'm surprised the valves sink into the the head that much with a modern engine. Very common in older engines with induction-hardened valve-seats that are part of the head-casting. Many cars and trucks have hydraulic cam followers that self-adjust so if those valves sink - we don't notice. I've got a Chevy Tracker with a 2.5 liter V6 Suzuki engine and it has over 300,000 mile on it and the valve cover has never been off. I don't even know if it has solid or hydraulic lifters. I've never had to do any engine repairs so have no idea what is inside that engine.

[Derek up North]

Just got done putting new valve seals in my 22RE in my 1988 Mini-Cruiser. That went fine. I found the all the exhaust cam-follower clearances way too tight. Had around .005" clearance on all when checked cold, yet the intakes were fine. I assume that is from valve-seat recession over the years. Amazing the valves did not start to burn out. They would of soon.

What clearance did you set them to 'cold'. I only recall a 'hot' clearance for the 22R(-E).

[zero]

What clearance did you set them to 'cold'. I only recall a 'hot' clearance for the 22R(-E).

I set them approx .001" tighter cold. I've checked my 20R engines several times cold and hot and they barely differ by .001" (clearance slightly increases when hot). In reality I set them a tight .008" and .012" (hard push with a feeler gauge) which will plenty close enough for me when it gets hot. Toyota gives hot and cold specs on several engines but not on the 22RE (that I know of). Those specs are just a "safe compromise" on a mass-produced engine anyway. If someone was really a fanatic and wanted the engine set as close to factory specs as possible - guess you'd need a degree wheel and a dial-indicator and set clearance so the valves started to open at the exact correct time (like is usually done with race engines).

Back in the late teens - like maybe 1916 - two noted race car drivers had a argument about valve adjustment with Ford Model T race cars. One claimed using a feeler gauge was the best and the claimed a dial-indicator and degree wheel was the only way to go. So they had a show-down race with two supposedly identical Model Ts. Sorry - but I don't remember which guy won.

I know this. My engine is a heck of lot better now then those exhaust valves were so tight. I'm not about to take it apart hot just to verify. If it started making a lot of chatter - then I would.

[Derek up North]

I guess in an ideal World the valves would be adjusted at full operation temperature. But of course that's not going to happen! It takes time to remove the valve cover and it takes time to adjust all 8 valves, the engine cooling down all the time. Adjusting cold with an adjustment/allowance for the engine heating up makes sense to me. You'd think Toyota could figure out what temperature to set cold would give optimal clearances hot. Somehow I think the valve clearances on the brand new, never run, just assembled 22R-E engines installed in the vehicles at the Factory had the valves adjusted cold.

[snail powered]

I had the same basic job done recently. I have no place to do any major work on my 22r, so took it to a recommended shop in Klamath Falls, Lee's Automotive. They are very familiar with this engine, which was good. 3 studs broke getting the exhaust manifold off, but they did get them out without pulling the head. Once back together, it still leaked, so they had to pull it apart again, it was warped. Off to a machine shop, then back on and all was good. I felt that the $214 they charged was very reasonable.

Things are much quieter now! I can even hear a bit of valve clatter. I adjust them about every 12,000-15,000 miles. They were really tight when I bought it 3 years ago, a wonder there were no burned valves.

Steve

$214 was a great price! God bless small town America :-)

[zero]

I guess in an ideal World the valves would be adjusted at full operation temperature. But of course that's not going to happen! It takes time to remove the valve cover and it takes time to adjust all 8 valves, the engine cooling down all the time. Adjusting cold with an adjustment/allowance for the engine heating up makes sense to me. You'd think Toyota could figure out what temperature to set cold would give optimal clearances hot. Somehow I think the valve clearances on the brand new, never run, just assembled 22R-E engines installed in the vehicles at the Factory had the valves adjusted cold.

Toyota gives cold and warm specs for the 8RC engine. Why not the others, I don't know. I too find it hard to believe they were running every new 20R, 22R. 22RE, etc. at the factory for half an hour and then raced to check valve lash before the engines cooled down.

Back in the 60s me and many I knew adjusted the rockers on our solid-lifter Chevies with the engines hot and running. Not because we cared about the hot/cold difference. It was just easy. No worrying about the position of the cam. Just kept the feeler gauge in place and felt how it fit during the "loose" phase as the rocker moved up and down. It was a mess with oil leaking and squirting all over the place. But no EPA to worry about then, and oil was 39 cents a quart (for the cheap Foxhead stuff). In retrospect - I wonder how many times we caused the valves to hit the pistons by keeping the feeler gauge in there when the valves were opening.