cstem

Okay boys and girls and boy/girls, I have a 91 2wd 4cyl manual that is bone stock, has 130 k on it and AC. When driving on the freeway mostly(sometimes from a light) I will be doing 55-75 and will start to hear a ping, rattle that sounds like a valve rattle almost that gets worse then stops as I let off the pedal. It resumes as soon as I get back on it. This happens with AC on or off and usually when warm. It sounds like it comes directly from the drivers side mostly. I adjusted the valves not too long ago and it did not change anything. It still runs awesome and pulls hard when the pinging noise is happening and does not hesitate or anything. no noise at idle or on start up. No smoke either. I run regualr unleaded mostly. Also, Issem to notice it more now that the temp is above 100 degrees outside (I really cannot wait to move). I did a search and saw all kinds of ideas but no answers that showed a ture fix or what really was that caused the noise. So I ask for your help. Thanks in advance, Cory.

PirateFins

Does it sound like draging a can on a chain link fence? Does it only do it a certain RPM's like around 2k->3K. Have you checked the timming chain guides when you did the valve adjustment. If the guides are toast the chain is wearing on the timming/water pump cover and will eventually wear thru and allow water to mix with the oil. This is a known problem with 22re's.

BLKNBLU

iTrader: (1)

I think it's pre ignition pinging. I'm there with ya in AZ and I've been getting it the last several summers. I tried premium fuel for awhile but that didn't do squat. I put in a 3 row radiator a year or two ago and it helped some but it still does it from time to time on the hottest days when under a load like uphill with AC in the 110* heat . I'm not enough of a mechanic to know if dinking around with the timing would help but basically I'm not willing to move it back and forth seasonally. Fortunately for me, it's not my DD any more so it's not a real big issue to me. If you want to do the radiator, get the one for a turbo. It has the 3 rows and bolts right up to the stock mounting points so it's a simple swap out. Hope that helps although it's not really a resolution.

Mike

cstem

Thanks guys. Just replaced the radiator with one from BAP and the thing runs very cool. As far as timing chain rattle, I think it would happen at most rpms and alot of the time. This really only goes when on the freeway when it is hot and not when going say 40 in fourth, so rpm does not seem to be the culprit, rather load does seem to make the diff. Anyother suggestion?

LittleRedToyota

the timing chain rattle only happens around 2800-3000 RPM.

not exactly sure why--i guess that's just the right speed to get the chain occillating at the correct frequency to hit the timing cover or somthing--but it is well-documented that that is the RPM level it happens at. that will generally happen even sitting still (and you reve the engine to around 2800RPM), though.

only takes about 10 minutes to pull the valve cover and check for sure--not something you want to let go if that is the problem as you will eventually end up with all of your coolant in your oil pan.

having said that...it sounds more like pre-detonation to me, too (though it could be many things). especially since it only happens under load. try running a tank of premium and see if it goes away.

BLKNBLU

iTrader: (1)

I still think it's what I said. Mine runs right in the correct spot on the temp gauge, just below the middle. It's just too d%^& hot here.

2ToyGuy

AMEN and halelujiah! to it's being too dratted, stinkin, freakin, BLOODY HOT here! Amazing how many euphemisms there are for swear words, isn't it? I HATE THIS PLACE.
Of course, that may explain why, after 25 years, I'm selling and moving to OREGON! I AM OUTTA THIS HOLE! FInally.
Sorry for yelling, everyone...
/endrant/