MY NEW LC (1 Viewer)

[johnsonf18]

I recently bought a 1996 LC, white, no lockers with 151K miles. It was advertised locally as needing a new engine, $3000. I went to go see it and get some background on it. This is what I found

1. engine knocks upon start (sounded like from the bottom), goes away after start. Idles a bit rough, but he said he has not driven it much, its been at his mechanics shop. I drove it for about 20 minutes, and all temps, pressure, exhaust looked normal.

2. I checked the oil and coolant levels, both looked a bit low, but normal color and consistency. No leaks under the LC and no visably engine leaks.

3. All electronics worked, leather looked very good, needs new rubber, no body damage.

4. LC has a 3" OME lift.

5. No rust at all

So I asked him a bunch of questions, primarily on why he thought it needed a new engine. His mechanic, not a Toyo mechanic (mechanic at Carmax told him that the knock, was the "knock of Death". So the mech said he needed a new engine. I asked him if it overheats, and he said no. In fact his mech told him to drive it around till it overheats (no sure why), but he said he drove around for 3 hours last week and it would not over heat.

I would like to know what you all think might be the cause of the knock on start. I paid him $2k for the rig. I tried to be as specific as possible. This would not be my daily driver, I would like to do a HG on it, but I'm not sure if doing that repair has anything to do with the rod knock. BTW, the guy said his mech did the front and rear seals. Thanks

 

[rtarh2o]

What do you mean the knock goes away after start? Is it immediately after the starter is disengaged or after it warms up a bit?
Rusty

 

[johnsonf18]

I knocks about 4 to 5 times immediately after starting the engine (fairly loud). Then it does knock anymore

 

[johnsonf18]

So any thoughts on the "knock of death"?

 

[murf]

DOes it only do it when cold? Does it do it after sitting a few minutes while still warm.

Sounds like the bottom end is possibly getting sloppy or maybe an initial oil pressure issue?

 

[ShawnTRD]

What oil filter is on it? Try changing the oil & filter. I've see a lot of oil filters that have bad drain back valves making engine knock at first start. Get a Wix, or Napa Gold, or Toyota OEM. I would also get a can of SeaFoam and pull it in the engine oil and drive it home before changing the oil. SeaFoam will act as a gentle cleaner.

 

[johnsonf18]

I happens everytime it is started that I'm aware of. He did mention that they replaced the engine rod bearings, the rear seal and both oil gaskets recently. It sounds like a loud tapping in quick sucession, then it sounds normal. When I drove it no unusual smoke out ot the exahust and all the readings look normal. I have not started it at full operating temp yet. Looks like alot was done on the top, no HG, My wife said it sound like it came from the starter area. No leaks that I could see. thanks for your response

 

[bruff]

I am no mechanic, but I say you got a decent deal and you should just drive that thing . . . after doing all PM stuff.

 

[97LandCruser]

you should do a compression test then leak down if needed. possibly check for something wrong with piston/s. usually rod knock doesnt go away. i would try and fix prob now because if you wait till it breaks ( if soon not 2 years from now) you will probably have to spend anothe 2k or more to get it running again. head will warp if over heat and may machine shops wont work on the head and tell you it is warped beyond repair. but great deal.

 

[CycloSteve]

Good price indeed. Piston slap perhaps? I believe that you may need to pull the engine for that one.

My advice is to send a PM to Robbie (PowderPig is his user name), and see if he can help point you in the right way diagnosing your problem.



Steve

 

[johnsonf18]

I have an update, I noticed upon some further driving and listening to the engine, the knock is very faint while driving as well, speeds up upon acceleration and gets a bit louder. Additionally I noticed the oil pressure drops almost all the way on the gauge when at idle, then goes back to normal range when accelerating, stays constant when at operating speed. Appreciate all the assistance.

 

[Gammarho1]

My 95 does the same thing. It's a quick knock, then it runs great. I have 131k on the odo. So, are we saying to try sea foam placed directly in the oil?

 

[johnsonf18]

I think all the IH8MUD pro have gone to sleep

 

[Gammarho1]

I'm not too entirely concerned at this point. I'm going to change the oil and filter out and see what difference it makes. I just sold a BMW 5 series that did the same thing and ran strong.

 

[johnsonf18]

Do you hear your knock the entire time after its been started. My wife will bust me ass if this rig needs a new engine. I told her it was just minor so she agreed to let me get another.

 

[Gammarho1]

No. The engine sounds a little different than my 4runner, but nothing like a knock

 

[ShawnTRD]

Yes

http://www.seafoamsales.com/tech-info-gas-engines/

 

[jfz80]

have you tried a mechanics stethescope to isolate where the noise is coming from.

I had what in my mind sounded like a bad knock and the paranoia set in thinking the worst. I bought a 5 dollar stethescope and scoured every inch of the motor with it and found nothing.
I would try this and focus first on the oil pump cover, pulley mounts/bolts, water pump, alt, etc to rule out a bad accessory bearing.

If it is a bad rod bearing (shouldnt be if they have been replaced correctly and no damage was done to the crank) then A) you should hear it in the oil pan with the steth and B) if you put the truck in first gear and accelerate, when you let off the accelerator the knocking should get louder if rod bearings are bad.

Finally started with the simple stuff and it turns out it was a very worn drive belt. It was amazing how bad a bad belt sounded. I would have never been convinced if I didnt swap them one at a time and start between each to rule out a bearing.

On that note could it be a bad idler pulley knock? just sayin....dont overlook the simple stuff



best of luck, been there and hunting noises can suck
sounds like the engine runs ok, only thing I might try and confirm with a mechanical guage is low/no oil pressure at idle
but ive seen 80s here that did the same thing and are running fine like this for years (they are not the most accurate guages as well)

 

[Flank]

OP said that he heard the knock as a ticking... In my experience, the 1fz ticks. Just does, when running. I think you got a hell of a deal on this truck, so kudos. Now, get it to a competent toyota mechanic. It seems you got a hell of a deal by dealing with incompetent ones...

BTW - i love that... "The Knock of Death"... THAT is one competent mechanic. Otherwise known as "I don't know what it is, but I know it when I see it..."

 

[ShawnTRD]

Well John? Try changing the oil and filter yet?