Engine noise when cold and accelerating
#1
Engine noise when cold and accelerating
I recently rebuilt a 22RE for my ’90 4Runner using components from its original engine, as well as the block , pistons and rods and rocker assemblies from my (low mileage) 85 4Runner. The ’85 had a noise that I thought might be a timing chain/guide, and I replaced the chain and gears, installed new metal backed guides, but can’t remember if I replaced the tensioner ( I think so). The timing chain cover showed no signs of chain contact, though it looked like there may have been some chain contact with the sheet metal baffle inside the valve cover, near the filler cap. This did not cure the noise, and shortly after, my wife wrecked the ’85.
I bought the ’90 knowing it would need work, and the head gasket went in short order. One of the cylinder bores was bad, so I chose to mix and match parts between the two 22REs. The noise seemed to carry over from the ’85 to the ’90. The noise is shrill and sounds like metal on metal, but almost like sheet metal vibrating inside of a tube. It’s much like when the exhaust manifold heat shield on my ’82 22R cracked and was vibrating against itself, but neither 22RE has this shield in place but the noise sounds internal, like from inside the intake plenum, valve cover, or timing cover. The noise is there at startup briefly, but goes away after the engine comes up to temperature. It's hardly/not noticable at idle and It’s much more pronounced under the slightest acceleration, either in neutral or under a load while driving. I used a stethoscope, particularly around the valve cover and timing cover, but couldn’t find/hear the source of the noise. I’ve removed both belts, taking the alternator, P/S pump and water pump (new) out of the equation. I’ve disconnected vacuum lines going to the EGR in an effort to rule it out, but no change.
Could this be EGR/Emissions/Intake related, or does it sound like a bad tensioner? I’m kicking myself for not taking better notes (aside from all the internal clearances, etc.) during reassembly as to what was re-used from the ’85, but I was under pressure to get it back on the road. I really don’t want to pull the timing cover again, if the tensioner is not the problem.
Other factors: both valve covers and intake plenums were scoured clean, including all of the internal sheet metal baffles and passageways. New Engine Builder big valve head and cam, new (used) OEM exhaust manifold.
The engine runs great, gets good mileage – no other problems. Any ideas would be much appreciated.
I bought the ’90 knowing it would need work, and the head gasket went in short order. One of the cylinder bores was bad, so I chose to mix and match parts between the two 22REs. The noise seemed to carry over from the ’85 to the ’90. The noise is shrill and sounds like metal on metal, but almost like sheet metal vibrating inside of a tube. It’s much like when the exhaust manifold heat shield on my ’82 22R cracked and was vibrating against itself, but neither 22RE has this shield in place but the noise sounds internal, like from inside the intake plenum, valve cover, or timing cover. The noise is there at startup briefly, but goes away after the engine comes up to temperature. It's hardly/not noticable at idle and It’s much more pronounced under the slightest acceleration, either in neutral or under a load while driving. I used a stethoscope, particularly around the valve cover and timing cover, but couldn’t find/hear the source of the noise. I’ve removed both belts, taking the alternator, P/S pump and water pump (new) out of the equation. I’ve disconnected vacuum lines going to the EGR in an effort to rule it out, but no change.
Could this be EGR/Emissions/Intake related, or does it sound like a bad tensioner? I’m kicking myself for not taking better notes (aside from all the internal clearances, etc.) during reassembly as to what was re-used from the ’85, but I was under pressure to get it back on the road. I really don’t want to pull the timing cover again, if the tensioner is not the problem.
Other factors: both valve covers and intake plenums were scoured clean, including all of the internal sheet metal baffles and passageways. New Engine Builder big valve head and cam, new (used) OEM exhaust manifold.
The engine runs great, gets good mileage – no other problems. Any ideas would be much appreciated.
Last edited by t_main_99; 08-22-2011 at 05:33 AM.
#4
Its sounds like a problem I had not so long ago.
I looked at everything then I Guy I work with heard the noise and told me
It sounded like the speedo cable. Sometimes after years of use they dry out
and start to make a God awful sound, with mine mostly in the am when its
cooler or cold out and only for a short period of time. It stopped when the engine
warmed. So I replaced it and sure enough no more noise in the mornings.
I hope this helps!
I looked at everything then I Guy I work with heard the noise and told me
It sounded like the speedo cable. Sometimes after years of use they dry out
and start to make a God awful sound, with mine mostly in the am when its
cooler or cold out and only for a short period of time. It stopped when the engine
warmed. So I replaced it and sure enough no more noise in the mornings.
I hope this helps!
#7
I appreciate the replies and will try to record the sound this weekend. It can't be the speedo cable as it makes the noise when the vehicle is stationary, and it 's a new cable.
I've ruled out all belt-driven accesories by removing all belts and running it - the noise is still there.
Elsewhere on this forum somebody mentioned an emissions related reed valve that I need to read up on.
I've ruled out all belt-driven accesories by removing all belts and running it - the noise is still there.
Elsewhere on this forum somebody mentioned an emissions related reed valve that I need to read up on.
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