Noisy valves

The build-up is not likely. Usually the valves will pocket slightly at very high mileage while at the same time, some equal but compensating wear occurs in the overhead gear (cam lobes and valve follower) bring clearance back to something near normal. 36 thou sounds very wide. How is the rest of the engine? Has it high miles?

Jason

The car has 209k miles. I just bought it to fix it up and sell it. I paid $450 and the car, other than the valve noise is in very good condition. Is it possible that I'm just forcing the feeler gauge in too hard, actually compressing the spring a little? I'm trying to avoid pulling the head if possible, but will if I have too.

Yes, I have a suggestion. Don't pull the heads just yet. If you're showing .036" clearance instead of .012 and couldn't even purchase a large enough shim, I suspect something else is going on. My guess - just a guess, but I'd try this first, is that you have carbon built up on the valve faces from the prior owner perhaps idling excessively or never getting the engine up to high speed for 200,000 miles. Normally I would recommend Red Line complete fuel system cleaner, because it gently and safely and continuously removes carbon - but it takes a long time, like up to 10,000 miles, and you say you're just fixing up the car for a quick sale. So here's my recommendation. There's an old mechanics trick that many people hold in high regard. Actually you have two choices. Seafoam or distilled water. You can find Seafoam on the Internet or at NAPA stores and I think I also saw some at AutoZone. Seafoam was developed to clean outboard two stroke boat engines fouled with carbon and reportedly does a great job. Just follow directions. Something like pour it into the intake on a fully warmed engine at fast idle until the engine dies then let it sit for around 10 minutes. Then restart and ignore the immense cloud of billowing smoke at the exhaust, and drive the car until the smoke clears up. Method two is using plain water, which people have said works equally well without the smoke. Seafoam's MSDS sheets show light oil and naptha and despite their claims wasn't entirely persuaded this is completely safe for the O2 sensor, whereas with plain water, no contamination concern. Same idea, with the engine hot at fast idle slowly pour water into the intake, keeping the engine from stalling, probably a little less than one quart. If you have a lot of carbon build up, be careful about overheating the catalytic converter. Some have said it can glow orange or red from being overloaded with the exiting carbon - but they're designed to operate at high temperature, so should be no harm, just let it cool a while afterwards. Others have said they found a small pile of carbon below the tail pipe afterward. Caution: Note well --- do_not_ pour water too quickly because there is a risk of "hydrolocking" the engine if you flood it with water filling the cylinders with an incompressible liquid you can do engine damage -- so just trickle the water in slowly and there is no risk of hydrolock. You are essentially steam cleaning the engine, and supposedly you are cleaning it chemically as well it is said the carbon in the engine combines easily with the oxygen in the water. So by either method you should wind up with combustion chambers that are "squeaky" clean. I found the easy way to inject water into the throttle body, was to use a garden sprayer I had in the garage. Had a translucent plastic two gallon bottle with a pump to pressurize and then spray through a nozzle, so I just sprayed a small stream of water into the intake and white steam came out the exhaust. The catalytic converter did not overheat, and I did not find any carbon at the tail pipe, but had already been using Red Line, and valve clearances were in spec.

I'll give that a try today. Thanks for the suggestion. I had heard of this procedure before to clean up Jeep valves, and also read of some people using atf to clean the valves. It's definitely worth a try. Thanks again.

So I tried the water trick, and believe it or not most of my clearances are now around .015-.025, well within where they can be shimmed. Thanks for the help. I just finished measuring my shims and will be headed to the stealership tomorrow.

I've always heard the benefits of this "steam cleaning" and a good description of how people can do that here. But that's a lot of carbon build up!

I learnt something then. The stellite (or similar metal used in aluminium heads) seats must be very heat resistant, plus the valve heads similarly so. Glad the situation improved.

Jason

Is the water trick recommended for high mileage vehicles in general? I've got 135k miles on my '96 camry... I work only 3 miles away, and drive home for lunch to boot.

Mines the same,..a '96 with city miles on it 174,000ks. Its a bit noisy in the overhead too,..I might dribble a slight amount of water in its intake and see if things quieten down.

Hasten to add, the water is minimal. I'll get a squirter trigger bottle and use that to introduce H2O into the TB.

Jason (we are always learning,..just slow down with age)

How much distilled water to add? 1 gallon? 2? 1/2?

I'm tempted to do it with someone holding the accelerator to 2000 rpm... hopefully it will clean out the carbon deposits on my EGR valve too. (Which has proven very, very difficult to remove, I might add - I might have to remove the distributor just to access the pipe.)

Wal-Mart has a 2-gallon garden spray thing (hand-pump to pressurize, plus you get about two feet of flexible hose for the nozzle, very nice) but it's like $18. If y'all haven't noticed by now, I'm cheap... ;)

Oh, by the way... this steam cleaning reaction produces some carbon monoxide, too, so do this in a ventilated area!

Chemistry: C + H2O --> CO + H2

English: carbon plus water react to form carbon monoxide (Deadly Poison gas!) plus hydrogen gas

This reaction requires a high temperature to proceed (which is provided by the engine, how nice.)

Ive seen people pour a lot of water into older style engines with a vertical carby. A full cup of water poured over 1 minute or so. I dont recommend this amount as we have a horizontal throttle body and its just going to puddle in the TB and may cause problems.

I envisage filling a trigger-pump plastic bottle that is available in many department stores for general use around the house. Then while the engine is idling, turn the nozzle of the pump-bottle to "stream" rather than "spray", and then apply over a few minutes or so about 1/2 the bottle of water (roughly a cup) directly into the TB throat.

This just my guess. Anything more aggressive I'm not prepard to do, unless someone has an alternative experience.

Cant see why holding the revs up to 2000 will hurt.

A bit too large. Use a trigger-pak sprayer plastic bottle for about $3

Aye,..incomplete combustion is bad!

Jason

The way I did it was to remove a vacuum line from the intake manifold and spray the water into it. I tried pulling the intake hose from the tb, but the car would not idle with it removed. I ended up using a vacuum line that ran from the intake manifold over to the cruise control. I used a small 1/2 gallon garden sprayer to shoot a stream of water into the vacuum line. I have heard of using ATF for this, but I think it will kill your O2 sensor.

Thanx for the headsup on the TB intake tubing. Your way is tried and proven, so anyone reading my theorising on how to do it, please ignore.

Jason

Also, check your oil when you're done, because mine got a little bit of water in it in the process. Probably because of old valve seals and/or tired rings.

So, even after shimming my valves to within spec, I still have a top end knocking noise. It's not nearly as bad as before, but it isn't good either. Sounds like one valve instead of a bunch of them. I double checked all valve clearances, and because of the mileage on the car filled it with 20w-50. I inspected the timing belt too. I think I may have a sticking valve that is not closing fully and causing excessive valve lash during running. Any thoughts?

You can sometimes get a sticking valve to unstick by pouring a SMALL stream of ATF in the inlet while engine is running, at appx 1000 to 1500 RPM. It doesn't take a lot, maybe an ounce or two plus a lot of oil in intake could damage a catalytic convertor. HTH, Dave