Word to the wise....don't start telling anyone how great your rebuilt motor is working while still in the break in period......

Actually, I believe everything's okay, but the fan clutch engages a lot and I don't know if it's normal for it be doing so. I fear the motor may be running too hot.(No, I don't have a temp gauge that tells me the temp's....yet!)

A little briefing...
The O2 light had been coming on for the longest (even before the rebuild) and I could smell it was running rich. Mileage was getting rather poopy, too. So, until I could figure out why, I had advanced the timing 3* (22re) to lean it out a bit. Before that, I removed the EGR to see if that would cure it, but it didn't....although, both band aids helped. (Note: the valve body was damaged anyway....and I do intend to repair that and replace the TVV so I can reinstall the EGR)

Last week I'd replaced the AFM which cured the O2 light, but now the motor pings a little on hills. I can't imagine 3* would make that much difference, but I'm wondering if it's because of the 8*timing, no EGR, and new AFM combined and now the truck is running too lean causing the motor to run too hot. No indications whatsoever from the factory temp gauge of it doing so, and that's always been reliable enough in the past. And, no overheating. Coolant flow and t-stat action are all good.

I think I'd be more concerned if the fan clutch didn't come on at all. But, can a fan clutch go bad and lock up too much? Or, should I start looking at the operating temps?

I do intend to get a real gauge. Probably should do it soon, if I'm that concerned, eh.

 

I'd prefer the fan clutch to lock up instead of freewheel.
keep in mind too that it's summer and air-temps are higher.

the stock gauge without numbers- 'normal' is from 2/5 to 4/5 of the way up. I wouldn't really start worrying until the needle was 1/8 or so from the top line before the H. also, get the timing back to where it's supposed to be and get the egr back in if you can. egr lowers combustion temps- guess what that means?

 

Lol....yeah, I know all about the EGR. I'd read that autoshop site I love referring to about it's design and functions. So, that's been somewhat of a concern. I have to wait, though, until "dude" gets it together to ship all my used parts request. Plus, I have to have the EGR valve body welded. The threads stripped out a long time ago where the intake tube threads to the valve body.

The temp gauge sits where it has always sat.....about 1/3 from the bottom to redline. I did have some temp gauge overshooting for a while, but that's all long gone with a new t-stat and drilled hole.

The timing I just haven't gotten around to resetting, yet. It's only been the past couple days I noticed the pinging, anyway. I'll reset it tomorrow before I go hay hauling.

Anyway, the clutch always locking up is just annoying as hell. I know it's hotter and it would stand to reason that it should lock up, I'm just like,"Gahhh.....quiet please! Is this normal?!"...lol. Plus, I know they tend to suck the power and mileage a tad. Two things I don't really like the idea of. So, that's really why I ask. I wonder if that under the hood insulation stuff would help quiet things?

 

A fan clutch can go bad and either not work at all, or it can go bad so that its engaged all the time.

 

matthew-
thought about a flex fan? (not the electric one)

 

Matthew - Sorry to hear of your troubles. With the heat my fan has engaged just a little bit, certainly nothing I've taken notice of. Let me know if you need a hand. You know I'm not much for advice. So how'd you do with the AFM? Did you have to buy new or did you source a used one? Did that take care of the idle fluctuation?

Also, what % coolant - water ratio are you running? I'm running about 60% water I think.

 

I haven't experienced a 22RE break-in period (yet), but I'm working on it! What I CAN attest to is a break in on a small block 400cid I had in a 67 Camaro. That thing ran HOT for the first 700-800 miles during break in (guess that's a good indicator that it was tight). Could contribute to excessive fan clutch, perhaps??? Just a thought...

 

Uhm.....seems like I've looked into that before. I believe it was a cost prohibitive thing. What about them, though?

Oh, it's okay, Kyle. No "real" troubles....just bothersome. If it isn't normal for it to lock up so much, I'd like to replace it with whatever alternative. The constant noise annoys me.

I got the AFM from AutoZone. A reman'd ND unit like yours. Hasn't taken care of the idle, though. I'm waiting on another AAV (used) to see if that's the problem.

It's only the first initial idle on start up that I seem to have a major problem with, and the AAV is one major culprit. Otherwise, when driving around and coming to stop it idles pretty evenly.....though, it is on the low side. The timing is advanced and I even have the idle screw adjusted out rather far....so it doesn't make sense to me that it would still be low. Hmmm.....I hope it's just the AAV....lol!

 

Oooops....I didn't see this, at first. Thanks for the reply.

Would you care to explain this at all?

 

Thanks for the reply.

Okay....if you aren't sure, then I suppose I'll have to look into that. I believe I'm a little over 800 miles on the break in right now.

 

A flex fan usually allies to the older domestic engines that just had a fixed fan drive. The fan clutch design is a lot better as it responds directly to air temperature coming through the radiator rather than just flattening out at higher speeds like a flex fan does. My old fan clutch (probably original) did get tighter as it aged, to the point it was engaged most of the time. I kept it for a trail spare and put a new Aisin fan clutch on the engine. With the looser clutch, I picked up about 1 MPG with ho change in engine temps. You could also replace the silicone oil in the old clutch with a thinner fluid.

 

matthew-
4crawler answered the question about flex-fans. yes they were popular on engines that had a fan coupled directly to the engine. and since they flatten out at high rpm's, they relinquished some horsepower back to the engine at rpm without sacrificing cooling because the vehicle was moving and didn't need the fan to pull air across the radiator.

4crawler, mind if I ask you your proper name, at least your first? I'm sure I've seen it elsewhere but... It's nice to see your involvement around the forums since your are a respected member of the toyota community.
?

 

Ah ha!!!! So, it's just old.

Okay.....how does one replace the fluid? I didn't know that was possible.

 

matthew-
I'm not sure you should call the clutch bad. It is locking up when necessary and keeping your coolant within normal operating temps. Just because you don't like how often it locks up doesn't mean it's not working properly.
Actually, considering it is locking up and unlocking implies it is working.
You've said that the temp gauge is staying below half.
Sounds like the fan is working properly to me.

Just my 5 cents worth (I know, should be 2 cents but inflation ya know, and the cost of gas ).

 

I understand the flex fan thing, now. I thought you (Kirk) were talking about the "flex-a-lite" fans. Different entirely.

Okay....so maybe it is working when it should. But, what about when the motor's cold on a first thing in the mornin' start up? Should it be coming on then, as well? You see, I would think the fan should only come on/lock up when the engine is hot. And, that is should unlock when the motor has reached a certain speed....like out on the highway when cruising and the radiator is getting enough air. I thought that's it's supposed to work, anyway. It just seems like it comes on a lot more than it used to.....even since last summer. It did sit up for a couple of months in the winter. Don't know if that would affect anything. ???

BTW, if I may answer your question, Kirk. His name is Roger Brown.

 

the fan clutch is allegedly controlled by the air being drawn across the radiator by the fan and its temperature once in encounters the fan clutch. makes sense if you think about it. the clutch has no electrical or mechanical connection to the engine (other than the belt) from which to decide when to engage or not other than how hot the air coming off the radiator is

oh, and thanks matthew. I'm filing roger brown away as someone I want to know.

 

As far as the fan clutch locking up upon startup - I think they all do this. Every toyota I've had (86,87, 99, 98) have all done this on cold startup. They disengage within 1 min or less.

 

Ah....blast it! I guess I'll do some tweaking and see if it quiets down. If I start driving with road rage from the noise, I may get a new clutch.....or reoil....if 4crawler ever answers that one. May have to research.

Thanks guys.

 

shoot him a pm, he is good at responding.

lee

 

http://web.archive.org/web/200212100...fanclutch.html