rattle noise durring acceleration?

[jakegator]

hello, I recently bought a 92 explorer with 300K miles, the trans was rebuilt aprox. 5K ago and as far as I know the engine is extremely old. Usually when i go up hills or accelerate it will rattle between 2 and 3 thousand rpm. However it will rattle at other rpms and speeds occasionally. Im pretty sure it isnt a heat shield issue, i checked them and they all seem tight. Im concerned its the timing chain tensioner(s). I was told this is unlikely for the 1st gen engines but i guess anything is fair game with this many miles. Im just looking for input and suggestions as to what it may be or if it can be diagnosed? I did run codes engine off was 111, cm was 172,181,185,186,187. From what i can tell they wouldnt cause the noise but i figure id throw them out there anyway. also it doesnt make any noise when it is rev passed 3K in park.

Thanks for the help!
-jake

 

[Anime]

The 'rattle' is likely valve clatter from worn rocker arms. This is a known issue with the stock rockers, the material was too soft and they actually wear down where they contact the valves.

The only fix is new rocker arms. Not too hard, not incredibly expensive, but you need to get the valve covers off, and generally it's a good idea to take apart the upper and lower intake while you're at it and replace all the top end gaskets.

You can also do the timing chain, gears, guide and tensioner while you're at it, at 300K it would make a difference along with the rockers.

 

[jakegator]

Do you have to pull the engine to replace the timing chain and gears? And if I were to pull the valve cover would it be obvious if the rockers are warn?

 

[Anime]

You can replace all the timing components with the engine in the vehicle.

The rocker arm wear is a known issue, if it's got 150-200k on it, the rockers are worn. You can check by removing the rocker cover and feeling how much play there is in the rocker arm, but visual insection by removal will show the indentations.

 

[gmanpaint]

Deltacams sells a rebuild kit for around $200, with a core charge. I have the same issue in a 94 I have to contend with.

 

[MrShorty]

Usually when i go up hills or accelerate it will rattle between 2 and 3 thousand rpm.

What kind of "rattle" is it? At this age, valves/rockers/pushrods can be worn and make noise. However, another common "rattle" on this engine (especially while accelerating or climbing hills at highway speeds) is engine ping or spark knock. This is usually caused either by a dirty MAF (causing the engine to run a little lean which causes the predetonations) or by a loose lower intake manifold (causing a slight vacuum leak that causes the engine to run a little lean). If the rattle you are hearing is pinging (often characterized as the sound of marbles rattling inside a can), then you might try these types of things.

 

[jakegator]

The noise is more like nail/screws in a can, there isnt any pattern to the noise. I suspect the rocker arms. The first weekend of October Im pulling it apart to replace the head gasket so i will inspect them then.

Anime - I read somewhere about there being a timing chain in the rear, cna that one also be serviced while in the vehicle, or do I have bad info?

-Jake Thanks all!

 

[Anime]

If you're replacing head gaskets, you might want to consider just going ahead and doing the whole thing, replacing the heads as well. The new aftermarket heads are stronger, and have more material on them, and also flow better. The factory heads are a little thin and are known to crack, especially if the engine has ever overheated, which can happen fairly easily with a stuck thermostat. New heads are only a few hundred, and you can just throw in the new rockers at the same time, and of course all new upper/lower intake gaskets as well. New heads aren't a must, but just something to consider if you're spending money and doing the work anyway. You might even find a crack or otherwise have to replace the heads when you see what condition they are in.

The rear timing chain rattle issue is on the SOHC motors in newer Explorers, the 4.0L OHV V6 motors just have a single timing chain in the front, which is a lot simpler to replace, and a lot less expensive as well. If you had a SOHC motor you'd need to pull the motor to do the job correctly, the OHV just needs the stuff on the front pulled off.

 

[sucker]

What kind of "rattle" is it? At this age, valves/rockers/pushrods can be worn and make noise. However, another common "rattle" on this engine (especially while accelerating or climbing hills at highway speeds) is engine ping or spark knock. This is usually caused either by a dirty MAF (causing the engine to run a little lean which causes the predetonations) or by a loose lower intake manifold (causing a slight vacuum leak that causes the engine to run a little lean). If the rattle you are hearing is pinging (often characterized as the sound of marbles rattling inside a can), then you might try these types of things.

I went this route to fix my "rattle". Under acceleration, I was getting a rattle. I also had a rough idle, especially when it was warm and muggy. After cleaning MAF replacing IAC, plugs, wires, not much change. Then I found the coil threads and went that route. Pulled the #4 wire and it ran the same. Ah ha moment. Cleaned rust off coil and was little help. Replaced coil and am running smooth once again.

 

[dani9678]

Does this problem with the rocker rattle also apply to the 1995 and up Explorers with the 4.0 OHV engine or did Ford update the rockers?

Matt

 

[FR-425]

Codes you listed are all related to the engine running lean.

You've probably not only got ping but severe ping (spark knock) (pre-detonation)

The last four (184,5,6 &7) tell the story: The MAF is toast... ..