Hi, my name is Rob and I'm with Pulido's Automotive in Jacksonville, Fl. My partner here ownes a 1995 Landcruiser that I need a little advice on a noise it's making. The truck was using about 2 quarts of oil in between oil changes. We had the engine completely rebuilt by a local machine shop. They found there was two separate oil rings that were frozen and said that was the reason for the oil consumption. They cut the block to .40 to "clean it up" and replaced all pistons, rings, bearings, etc. The cylinder head was sent to a local cylinder head rebuilder for complete valve job, pressure test, resurface, stem seals, valve adjustment, etc. We installed all new oil pump gears, power steering pump rebuild kit, you get the picture. We did everything that we could while engine was apart, including water pump and timing chain stuff. To make a long story short, the engine has a definite valve train noise coming form the valve cover area. Oil pressure is good, it doesn't appear to be using any more oil. The cylinder head company came to our shop and rechecked the valve clearance, and shim integrity. They found six of the valves to be too tight. Toyota couldn't supply the exact correct shims so the tech "ground" the shims and checked them with a micrometer. After all this, the noise is still there. When you take off the plug wires one at a time to kill the individual cylinders, the noise stays as well. On cold start, the noise is more pronounced, and gets lighter in the first ten seconds of running. Everyone is pointing the finger at the other, and we have gone as far as to take it to the Toyota dealership. They removed the valve cover and made several recommendations as far as distributor gear lash, cam gear lash, etc. None of these have made any difference. We are not in the motor rebuilding business, but do our fair share of cylinder head gaskets. Other shops refer cylinder head work to us as well, so I think we have a good base knowledge of how it "should" work. My question to you is, have you ever heard of such a thing after a rebuild? Has going .40 over caused this issue? It sounds just like a miss adjusted valve train to me. Is it possible that the machine shop ( or our tech for that matter ) may have bent a camshaft slightly when torquing the caps down or something like that? We are pulling our hair out over here. 2000.00 dollars later, it doesn't use any oil, but sounds like a diesel. And helpful hints or suggestions to look at it from another angle would be a HUGE help. Thanks in advance.
Engine Noise after Rebuild
- Thread starter cruisinalong
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first, the shims that were ground need to be hardened again if that wasn't done.
Also the gear on the exhaust cam is a zero lash type. If you look closely there is actually two gears there and they are spring loaded to provide zero backlash. When removing the cam shafts a M6 bolt is used to hold the gears in proper position while out of the head. Was that done?
Also the gear on the exhaust cam is a zero lash type. If you look closely there is actually two gears there and they are spring loaded to provide zero backlash. When removing the cam shafts a M6 bolt is used to hold the gears in proper position while out of the head. Was that done?
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That was one of the things that Toyota supposedly checked... They said all that appears to be fine. The way that it sounds is very rythmic, like a camshaft/lifter contact noise. How can the backlash be checked if the head is completely assembled? Or can it? We REALLY appreciate your input.
i thought they all made lots of noise??? good luck, but atleast you arent loosing oil anymore
Dead lifter? Does Toyota use Hydraulic lifters? (recently ran into this problem with a Porsche 951)
Valve springs correct installed height, retainers not hitting the valve guides? Tappets not hitting anything, tappet bores not oversized?
Valve springs correct installed height, retainers not hitting the valve guides? Tappets not hitting anything, tappet bores not oversized?
Well I would still check it myself. If you pull the valve cover you should be able to install that service bolt if things are installed correctly. If you can't then the gears aren't set right.
For others this engine doesn't have hydraulic lifters, in fact it doesn't have lifters period. It's an overhead cam with a shim in bucket setup.
We've actually had a couple surprisingly accurate diagnoses here with audio files either posted on YouTube or the like if you want to try that.
Assuming the timing chain was correctly installed (there is a common mistake on the timing gear installation because it fits about 30 degrees off or correctly) and the timing chain tensioner was replaced (would be logical at this amount of engine work), and the cams were timed correctly then the valve train would remain the suspect. Was the engine difficult to start after reassembly, or did it fire up the first time correctly?
DougM
Assuming the timing chain was correctly installed (there is a common mistake on the timing gear installation because it fits about 30 degrees off or correctly) and the timing chain tensioner was replaced (would be logical at this amount of engine work), and the cams were timed correctly then the valve train would remain the suspect. Was the engine difficult to start after reassembly, or did it fire up the first time correctly?
DougM
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Was a service bolt installed in the exaust cam before disassembly? if not then you have lost the spring loaded tension on the scissor gear on the exaust cam allowing the cam gears to rattle against each other.
Just want to follow up on this. Did you ever find out the cause? I've got the exact situation going on now with 100 miles in.
Thanks!
Thanks!
Have you tried to use a mechanics stethoscope to isolate where the noise is coming from? The steering pump was part of the teardown it maybe that the gear was damaged. It doesn't take much to make a rhythmic noise.
Did not consider this as it's a new pump with the old gear. I'll look into this too.
OP hasn’t been seen in 12 years…
I confirmed it was the pulley/gear. I replaced it and now the engine is purring.
Very common issue. Sounds like all the world it is valve train noise...but if you target the driver's side of the engine with a mechanics stethoscope it can be narrowed down to the PS pump area...which is invariably a damaged or misaligned gear.
