strange valve noise

[ak_kletus]

I have a '95 Toyota pickup with the 4 cylinder engine. I just recently purchased it and love the truck but am still getting used to it and the noises it should/shouldn't be making. Here is my question:

When I am accelerating and shifting the engine will make a "rattling" type noise. It isn't a valve tick I'm very familiar with that sound. It almost sounds like the engine is dieseling (the sound you get when you turn an engine, usually diesel, off and it still runs for a second or two). It seems to be coming from the valves or at least that area, so I guess it could be anywhere in the engine. The noise only comes at higher rpms (around 3000) and never under load. So if I am accelerating or decelerating or at idle everything is great. With a manual there is always that brief moment when you push the clutch in that there is no load on the engine and it is still at a higher rpm. That's when I get the noise then when I shift its gone again. The noise is fairly loud and certainly noticable. Enough so that I am a bit worried what it could be.

Any thoughts? I don't know if these are hydraulic vavles or not. It could be that I need to adjust them. It also could be a bearing somewhere in the engine is bad. Or it maybe a normal sound for an engine with 96000 miles on it. Perhaps a timing chain is loose (I think this has a chain and not a belt).

Thanks for the help!
mark

[Bakemono]

Perhaps it needs the spark plugs replaced. If they are worn-out, it could develop a miss.
Try replacing the spark plugs and see if the noise goes away.
Cap'n

[ak_kletus]

Certianly worth a shot. It is probably about time to do that anyway. I haven't ever had to pull one yet.

thanks

any other ideas?

[burger]

What kind of oil are you using in Alaska?The timing chain tensioner works on oil pressure.Maybe when your truck is warm and the pressure is lower and it's slackening up when you shift.Aftermarket timing belt tensioners tend to loose their spring pressure fairly quickly as well.I'd haul off the cover and check to see how sloppy the chain is.

[Sidney]

Most engine wear on any engine occurs at startup with that said the R series Toyota engines such as the 18R,20R and 22R all use a timing chain which it's tension is supplied by hydraulically driven timing chain tensioner which has it's oil pressure build up few seconds after the engine has started therefore the timing chain rubs on the driver's side brown colored nylon/plastic timing chain dampener or guide and after so many miles (140-170 000 miles in the city with the average 4 starts per day) the driver's side guide breaks through causing the chain to rub on the timing chain cover for the first few seconds upon startup and when driving in 5th gear and letting off the gas.
Usually by this point the other timing components such as the camshaft sprocket,crankshaft sprocket and chain have their specs out of tolerance and hence must be replaced as well.The tensioner sometimes sticks due to dirt build up and other problems arise as well and must be replaced as well,all of those parts are sold in the aftermarket world as a "timing chain kit" which also include gaskets and a front oil crankshaft seal.Toyota on the other hand for some reason does not sell the parts as a kit but as individual parts which would cost around $400+ and from all of the reading I have done on many Toyota 4-Runner/pickup discussion sites I have come to the conclusion that many experienced off-roaders who cannot afford to buy all of the genuine Toyota timing parts instead buy the chain and tensioner from Toyota and the other parts from aftermarket as a kit but of course don't use the aftermarket chain or tensioner.
The best brand of aftermarket timing chain parts to use on the 20R & 22R series Toyota motors are:

http://www.engnbldr.com/ToyotaHotlicks.htm
http://www.22r.biz/
http://www.rpmrons.com/toyotatiming.html
http://www.toyota-engine-parts.com/
http://www.europeanautomotive.com

and if you choose to buy from Toyota these places have the best prices in the USA & probably the whole world:

http://www.1sttoyotaparts.com/partscat.html (10% shipping)
http://www.toyotadiscountparts.com (free shipping with $100 & up)
http://www.Toyotaparts4U.com
http://www.toyotaofplano.com

Other ways to check timing chain wear are:

http://www.misterfixit.com/chanslop.htm

you can also remove the valve cover and take a flashlight and see if the driver's side timing chain dampener or guide wore through.

You can bend 1 to all 8 valves and have timing cover eaten through if you wait and then coolant and oil mix together to give you butterflies in your stomach.You can do a fluid analysis on your engine oil by going to any Caterpillar and buying a fluid analysis kit for around $15-20 and taking a sample of your old oil.

Finally these sites explain the timing chain replacement well:

http://yotarepair.com/22R%20timingchain.html
http://www.4crawler.com/4x4/CheapTri...ingChain.shtml
http://www.4x4wire.com/toyota/maintenance/timingchain/

Sidney® ™
Repairs tv's,vcr's,home/car audio out of my home
E-mail:sidneybek@yahoo.com
Dartmouth,Nova Scotia
Canada
1985 Toyota 4-Runner,solid front straight axle,factory cruise
control,sunroof,22R-E,W56,RN60LV-MSEK,rusted rear step/towing chrome
bumper with 244 000 KM

[ak_kletus]

That is some great advice. I will work on examing the chain and tensioner this weekend.


mark

[Toy Sport 4x4]

I would check timing before timing chain, but 22re engines are bad about timing chain guides breaking and chain rubbing timing cover.

[ak_kletus]

Well I tried everything I know to do. I replaced the cap, plugs, rotor and wires, all the filters and cleaned the injectors. I tore open the engine and replaced the timing chain as well and I still have the noise.

I did make a scary discovery though. Once I had the timing chain cover off it was obvious that the chain had just been replaced. It also had a new timing chain cover and there were marks where the chain had rubbed on the cylinder head. This really makes me worry. Worst case I can think of is that the chain wore through the cover and coolant flowed through this engine for a while. If that happened then I could have rusted bearings. Would that make a rattling noise like hear? I have no idea. I suppose it could. Maybe I am just paranoid.

I have read several other posts on this site that seem to have the same noise problem. Has anyone figured it out yet?

[archer1]

sounds to me like it may be simple pinging. try some high octane gas for a bit and see if it helps.

[ak_kletus]

I did try that as well. I even played with the timing some. I actually have it advanced a degree or so to much right now so I need to move it back because it is pinging a little. They are very different noises. The rattle is much deeper than the pinging sound.


I have also adjusted the valves a couple of times. They all seem to be right on though, and haven't needed to be adjusted.

[bvenvert]

I have a 1986 Toy SR5 turbo pickup with a similar problem that is in the shop at this time. I took it in to get the valves adjusted and had them check the timing chain guides. The driver's side guide was gone and had been shredded into the oil pan. The timing chain was slapping the side of the cover, which will eventually lead to problems with the cooling system.

Since I needed new guides and you have to tear off the front of the motor to install them, I ordered the timing chain kit from engbldr which includes the metal driver's side guide. I am having it installed this week, which should correct my problem. I am having the valves adjusted at the same time.

I suspect that you have a timing chain issue.

[ak_kletus]

I actually have just replaced the timing chaing, and guides. I thought that was the problem as well. I have adjusted the vavles twice, but only by myslef. I think it might be worth it to take the truck in and have the vavles done by a shop and see if that does it. I am certianly not the worlds greatest mechanic.

Maybe that will do it.

[kuto]

i have the same problem as you kletus...mechanic told me using oil thicker than recomemded can cause this noise, wat grade oil do u use?...i havent rectified my problem though...hope to go to the shop to fix it soon, i personally cant figure it out as yet

[ak_kletus]

I took the truck into the dealer. Bad news. I have a rod knocking. So time for a new engine. Does anyone have any advice about this? Should I buy a crate longblock from NAPA or take mine to a good machine shop and have it rebuilt? Price will be about the same both ways.

[burger]

I'd go with whoever will give you the best guarantee or warranty if the price is the same.