cold knock under load for few minutes

I ran across a guy who wrecked his ranger that has an 88TC motor in it, and he's selling the motor for 100 bucks. It runs fine, but we have no idea of the mileage. Problem is that it very lightly has a knock when accerating, for about the first 3 to 5 minutes of driving then it goes away. I've read it's anything from the rod/crank bearing to the wrist pin bearing to piston slap which requires a hone and new rings. What's the normal cause of this noise?

If it's the crank/rod bearings I've read here you can just replace the bearings. Do I need to buys special bearings or stock size? Do I need to buy new rod bolts? I'm thinking of buying it for my ranger since he has all the wiring and everything.

I could be crank knock or piston slap.If there is too much timimg, it could be spark knock.

A worn wrist pin hole doesn't stop knocking when it get warm, especially if it's like 1/8" over [Image: biggrin.gif]

This is currently posted at TF: http://www.turboford.org/ubb/ultimatebb....2;t=036563

Bearing noises get worse with heat, when the oil is thinner.. Slightly noisy cams can get better with heat, but the noise doesn't vary with load.. The only cold knock that goes away when warm is a piston slap, usually there is too much skirt clearance. Time for a new piston(s)..

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Three 1988 Turbo Coupes .....
And now a 1987

Hum. After I posted I remembered I have heard that sound on my tc when the automatic was in it. In reverse ready to back out I could hear it for a few minutes in the morning. I know it's the same noise now. I wouldn't say knock, like a deep tone, but somewhere between that and a valve click. It's not any of the pinging or other iginition related noises I've heard. This sucks, I'll have to listen to mine closely now when I get the drive train back in.
When I heard the motor in the ranger I thought it almost was an hla but noticed it was only under any kind of load. I found a few posts here and turboford to believe it's not a really isolated thing with these motors. Any idea of the failure rate and time is for something like this?



[This message has been edited by Matt S (edited 03-19-2005).]

While I've never had a piston problem with a turbo 2.3, I've had/seen many NA 2.3s knock under load when cold. Seen everything from a slightly worn skirt, to completely missing skirts.

If you let it warm up for a few minutes before putting a load on it, my guess is it still has some time. BTW boosting a cold turbo engine is one of the worst things you can do, short of detonation and overheating...

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Three 1988 Turbo Coupes .....
And now a 1987

Cool thanks for the info. From reading around on the internet I made a decision that it's not all that bad, but not great either. After all, millions of chevy trucks and some fords have this problem from the get go and are still running. Apparently pretty common in diesel also.

Correct me if I'm wrong in my thinking here but at least for my car, all the cylinders still had their cross hatch as far as I could see down to bottom center, so there's not much wear from it at all. Compression is perfect and I don't burn oil. So I'll just drive it and keep my ears on. Duly noted on the extra warm up time also (regardless of the heckles from the passengers "what are we waiting for??). Anyone experienced or heard of failure from slap?

So far as the ranger engine, the guy (who I ran into at work) said he decided to keep it all for another truck.

[This message has been edited by Matt S (edited 03-20-2005).]

Hey Matt,
Our cars have forged pistons that have get hot to swell up to size to fit the cylinder walls properly, and in the colder temps like this time of year you will notice it more pronounced and longer till they expand, I really noticed it on my 83, and my latest daily driver(88) also has the noise, but not as pronounced, until warm. Both of them about 3 to 5 mins under a slight load, or idle for about 10 mins, and the noise goes away, by the way I bought the 83 with 89,000 on it, and sold it with 150,000 on it, and it never blew up, the engine is now in a ranger going strong at 175,000 or so and thorouly abused!. Hope this helps you out.

2birds

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87 T/C,base, 5spd, bright red metalic, 136,000 miles, mods: auburn diferential with 3.73 gears,140 mph speedo,adjustable cam gear set at 4degrees advance,Gillis valve set to 16 psi, and of course the A&A wing.Had this one since 1992. My pride and joy of the fleet. It will always be the favorite.
88 T/c,semi loaded, auto trans, 179,000 miles also bright red metalic, is this the only color these cars came in? lol. was daily driver, and is now totaled,now it's a parts car.
88 Turbo Coupe,loaded 104,000,5spd,bright red metallic again, I can't seem to get away from this color!LOL, Soon to be the new daily driver.
88 Turbo Coupe,Fully loaded, auto trans, 105,000,Charcoal grey, Yes! I finally got somthing other than Bright red metallic!
One of the last 2 will be the new daily driver, not sure which?
Been to Carlisle 2002,2003,and 2004, met alot of cool NATO people and had a blast!

Good to know thank you. I only drive in the summer but I've never heard a noise idling, just under a load. Otherwise it seems in really good shape.

Matt - I have had my 88 since new and I can tell you that mine has had that noise since then. I remember taking it in under warranty and the shop foreman told me that it was "an EGR sensor". When I called him on it he said that we could get zone involved - they said that it was indeed piston slap. I did not want them fooling with the motor so we made an agreement to pay attention to it and do something later if required. At 145K the noise is still there and not any different - motor uses no oil and runs great. You should be OK....