1FZ cold start engine knock...whose got it?

[SBFJ60FIG]

So...this is my second FZJ-80, the first one (a '97) I bought with the motor out and I did a bench rebuild and I swear, it also had a bit of a cold start engine knock; I'm sure this is wishful thinking however.

Anyway, so fast-forward to my current LEX-ZJ, which has a bit over 175k on the clock. So she has, what is for sure a bit of a knock (certainly a rod knock) until oil psi builds, last < a second. My concern is that this knock may grow into a full-on rod knock. Meaning of course, that she knocks when the motor is running, warm, when revved, et cetera. Which it most certainly will, but the question is will this be in 100k miles or 20k?

I've been fishing for a blown 1FZ circa '95 or newer to just rebuild and have ready to go. I'd rather rebuild on my own time and then just swap in the freshly rebuilt motor over a weekend. Anyone got one near Chicago??? Much better than waiting weeks for a machine shop to do their part. And, the current motor could probably use a head gasket prior to the S/C being installed, and the pan looks to have a leak, and and and...it's really leaking oil from a lot of spots so I'm inclined to pulling the head, timing cover, and pan(s) all at once and do a reseal save for a rear main. Now...if I do all that and then a year or two later my start-up knock becomes, shall we say omnipresent, that would suck a big fat something, given all the reseal/HG work I'd recently done.

So...just fishing for what you all have in experience with your 1FZ-FE motors with cold start knocks???

 

[landtank]

I bought a truck with a rod knock when hot, my son's 95 has the start up knock, a customers 96 has it. IMO it's the next failure item on these engines.

Now everyone flamed me on doing HGs as a pm so I don't think that will change when I say that I would drop the pans and swap out the bearings. I'm planning on doing this on my son's truck.

I just got my engine back from the machinist. It had 288k on it and he said the crank mic'd out just fine. So I think that a bearing swap is just the ticket for these engines with the start up knock.

 

[SBFJ60FIG]

Thanks Rick, not a bad idea...I've never swapped bearings on a motor as PM...a shop I used to work at, we had terrible issues with replacing two-piece rear main seals on 4.0L Jeep motors. Nearly every one would end up with a knock after replacement.

But I guess it would not be too tough to just swap some rod bearings as long as the pan was going to be off for re-seal. Last 1FZ crank I brought in did not get ground either. In fact, I don't think I can recall having a Toyota crank ground??? But it's been awhile since I was rebuilding on a sorta regular.

And I'm with you on a PM HG, I'd rather do it in the comfort of my own garage, then deal with a less-qualified mechanic on the road that I have to pay!

Still gonna keep my eyes out for a 1FZ nearby. I do really like the idea of having a super fresh motor to just drop in!

Jason

 

[theallpowerfulme]

My 1996 has the cold knock with 136k on the clock. It improved slightly when I went to a better oil filter (wix/napa gold or toyota would be the ones to use - they have a better quality anti-drainback valve). I don't know how rod bearing replacement would help anything, the cold knock is almost certainly a lack of oil/oil pressure at startup. It should also be said that my 80 has a leaking upper pan seal and possibly a leaking front main seal. The main seal leak could contribute to a lack of pressure at startup.

I have been thinking about installing one of these to eliminate the knock on startup

 

[landtank]

My 1996 has the cold knock with 136k on the clock. It improved slightly when I went to a better oil filter (wix/napa gold or toyota would be the ones to use - they have a better quality anti-drainback valve). I don't know how rod bearing replacement would help anything, the cold knock is almost certainly a lack of oil/oil pressure at startup. It should also be said that my 80 has a leaking upper pan seal and possibly a leaking front main seal. The main seal leak could contribute to a lack of pressure at startup.

I have been thinking about installing one of these to eliminate the knock on startup

I think there is two sources for a knocking sound. One being the relaxed chain tensioner which is hydraulically operated. The other is a rod knock.

 

[timer00]

My 94 with 106k has a knock on cold start that last for about a second .. When I got the truck I don't recall hearing it when driving it home from Philly and any other time before the oil change I just had.. I am going to go to Mobil 1 synthetic and a good premium filter since my local shop used basic stuff and see what happens.

 

[darnold87]

Mines's got it... lasts about 1 second on a cold start... 175K on the clock.

 

[fj80toyman]

My '95 has had it for a long time, can't even really remember a time w/o it. I always thought (and still do!) that it's not rod knock, that sounds different than what I'm hearing. I believe it to be piston slap noise that occurs until the walls get lubricated.

I bought a '94 with a terminal piston slap (confirmed after teardown that #1 piston/hole was bad) that had the same sound that mine does only all the time, not just the first 1 second after startup.

On my most recent oil change (NAPA 1515 o/f and Mobil 5000 non-syn 5W-30, + 1 quart Lucas synthetic additive) that the startup noise is dramatically reduced from previous.

I keep hearing it, but even at it's worst doesn't seem to be getting worse or longer in duration, so I'm driving it like it's only a character trait, a little cold-blooded, or maybe feeling it's age like me!

Dan.

 

[hsiaoer]

Road trip? I've still got my old engine sitting in my garage... It spun a rod bearing, so it'll need a new crank, but didn't you say you were going to come get it?

 

[hsiaoer]

That one did have a cold start knock. My new one does not at all, nice and quiet from the get go.

 

[SBFJ60FIG]

That one did have a cold start knock. My new one does not at all, nice and quiet from the get go.

I do still want that bad dog...GF was talking me into a road trip to S-Utah yesterday...told her if we went we'd be picking up a motor too! I bet that crank might even clean up or just be ground and work!

And yes, the snowmobile trip, engine fetching trip did not happen. Could you deliver it to Sandy? Hah! I'm sure my uncle would LOVE to have an engine sitting in his garage until I got there to pick it up!

My '95 has had it for a long time, can't even really remember a time w/o it. I always thought (and still do!) that it's not rod knock, that sounds different than what I'm hearing. I believe it to be piston slap noise that occurs until the walls get lubricated.

I bought a '94 with a terminal piston slap (confirmed after teardown that #1 piston/hole was bad) that had the same sound that mine does only all the time, not just the first 1 second after startup.

On my most recent oil change (NAPA 1515 o/f and Mobil 5000 non-syn 5W-30, + 1 quart Lucas synthetic additive) that the startup noise is dramatically reduced from previous.

I keep hearing it, but even at it's worst doesn't seem to be getting worse or longer in duration, so I'm driving it like it's only a character trait, a little cold-blooded, or maybe feeling it's age like me!

Dan.

I agree that it might just be a trait of the motor...but I might just try some "engine in a bottle" and see if that helps. But really it's not that big of a deal and does not have me too concerned that it's going to turn into a bad rod knock anytime soon.

I think there is two sources for a knocking sound. One being the relaxed chain tensioner which is hydraulically operated. The other is a rod knock.

Having had plenty of 22R motors with broken timing chain sliders, this to me sounds for sure like a rod knock. But...many people DO NOT know what a rod knock sounds like.

I have been thinking about installing one of these to eliminate the knock on startup

Goodness...I would not put one of those on my motor, way way way too much trouble for negligible results IMO. Plus, I'm sure it's a PITA to install, and I would not want to plumb into my oiling system in a way that could later have me end up causing more damage from say a massive leak!

 

[js93cruiser]

my 93 doesent do it...228,000 on the clock

 

[js93cruiser]

but my dads 96 lx with 110.000 miles does..

 

[landtank]

my 93 doesent do it...228,000 on the clock

but my dads 96 lx with 110.000 miles does..

that's because the 93 model year 1FZ-FE got a ratchet style hydraulic chain tensioner.

It doesn't relax when you turn off the motor

 

[SBFJ60FIG]

that's because the 93 model year 1FZ-FE got a ratchet style hydraulic chain tensioner.

It doesn't relax when you turn off the motor

Ok, from one guy who (thinks) he knows a rod knock when he hears one, this does not at all sound like t-chain rattle to me. Not to say that others might be hearing chain slap, but this sounds like a rod knocking to me. I guess if I ever get to putting in conn-rod bearings there would be something to be seen on the old ones??

But...I will more closely monitor it, maybe make a log. From my recall, it does not happen at all times. And seemingly inconsistent to when you would think it would happen.

E.G., having sat for 3-4 days and then is started. Dunno, I'll pay closer attention and see what I can see.

 

[lndcruz]

this isn't the rattling noise is it?

 

[SBFJ60FIG]

this isn't the rattling noise is it?

No no...this is the low "knocking" of a conn-rod. Guess maybe it's time for a YouTube video for clarification eh?

 

[lndcruz]

No no...this is the low "knocking" of a conn-rod. Guess maybe it's time for a YouTube video for clarification eh?

Didn't think so, but when I saw this thread it made me think.

 

[BigOldCrusier]

Didn't think so, but when I saw this thread it made me think.

I have 289,500 miles and I also hear this knock noise you all talk of on a cold start. I bought the car about 2 months ago for $400. Running Castrol 10w40, premium filter and I hear the noise. How hard is the chain tensioner to replace?

Here is a video of the noise. Listen closely right after start up and you can hear it.

 

[IdahoDoug]

Sounds like the timing chain tensioner to me and quite like dozens of healthy 80s with lots of miles I've heard start over the years. Dunno why, but the website viewer only let me rewind it once to hear again then started pissing me off.

DougM