Motor Rap Upon start up

[sinkrun]

1989 4.0 155,000 motor is realy noisy for about 30-50 seconds when I first start it. The oil light hangs on while this is going on also. Coulpe of people said it sound like rods or bearings. This truck had 300 miles put on it in two years. Could it just need cleaned out or is it on its death bed? Oh I have put about 3000 miles on it in 3 months changed the oil twice and it does help some with the noise and light time.

[beaterjeep]

What weight oil are you using? Also synthetic, or dino? Very possible it's lifter tick, and can be 'quited' with a little heavier oil, but that just masks the real problem.

[sinkrun]

Regular 10w-30

[summerinmaine]

Sounds a bit like the rod knock I've got (only lasts about 5 sec on start-up however). But with 300K on the motor, can't complain.

 

BTW I use 20-50, but it's pretty temperate down here.

[Eagle]

IMHO 10W30 was too light for a new engine. I ran my '88 XJ on 10W40 up to about 175,000 miles, then I switched to synthetic. I wanted a light viscosity for cold winter starts, but enough body for highway cruising and wheeling in hot weather. So I've been running Castrol Syntec 5W50. Good stuff.

 

By the way, be sure to use an oil filter with a good anti-drainback valve. I use only Purolator. Do NOT use a Fram oil filter.

[dasbulliwagen]

I agree with the Castrol 5w50. Been using it in my Hyundai Accent since I bought it with 36000 on the clock, I now have 147000 on it and it still runs as strong as the day I bought it. Though if you have a rod knock, you may want something heavier on the cold end like a 20w50. That might buy you some time if it really is a rod knock. I am currently using Castrol High milage in my MJ. Owner said he replaced thee engine at about 140000, Clock now shows 341000, so I assume my rebuilt engine has 200000 on it. Afraid to put synth in an engine with such high miles......sorry if I hijacked :doh:

[bigd44889]

ok nobody has told u what is wrong yet just how to mask it

the probem is just the motor is wore alot

it needs rebilt before it does start knocking

when u start it it rattles and knocks till oil presser builds up

when the presser builds up it it puts that little bit of presser between everything

and quitsmaking noise

[BLHTAZ]

I think I would try having the rod & main bearings replaced. At 155K, the engine should still have a lot of life left in it unless it has been abused.

[JeepcoMJ]

ok nobody has told u what is wrong yet just how to mask it

the probem is just the motor is wore alot

it needs rebilt before it does start knocking

when u start it it rattles and knocks till oil presser builds up

when the presser builds up it it puts that little bit of presser between everything

and quitsmaking noise

 

the ONLY reason a motor gets this way is when someone uses chitty oil filters. Fram, K&N, and ALL OTHER performance filters are junk. as Eagle said, you need one with a superior anti--drain back valve (basically a back-flow-preventer). this keeps oil up in your valves and lifters after you shut it off rather than draining back down like performance filters do.

 

make no mistake, "performance" filters do nothing but destroy your motor. they're no good, and don't have the good qualities of other filters.

 

filters I'd run in my motors

WIX

Purolator

genuine MOPAR

 

that's my list. that is all I'd consider running. on a H.O. 4.0 the only filter I will run is genuine MOPAR it has the most superior filtration and back-flow prevention of all of them. this means no metal on metal contact at startup, and no particles getting where they don't belong.

 

-Pat

[bigd44889]

i agree about what filters to run

and thay may have helped cause the problem

but changing the filter now won;t fix the probem he has

only real fix is rebuild or at least mains

anything else is just a bandaid

[JeepcoMJ]

i agree about what filters to run

and thay may have helped cause the problem

but changing the filter now won;t fix the probem he has

only real fix is rebuild or at least mains

anything else is just a bandaid

 

 

yup.

 

I always suggest, for a motor rebuild, grabbing a motor for cheap that runs, tear it down, reseal, and add any performance parts you wish...then swap, and keep the old one for a spare.

 

if you can't keep the old one as a spare, then sell it for a hundo and get some coin back.

 

 

to re-iterate my previous post...the reason motors get that way with chitty filters is that people get in and start pounding the motor right away, before the oil has any time to get to the moving parts and lubricate.

[sinkrun]

Thanks for all the input and ideas I was just thinking about looking for a motor to get ready to build. Or a HO swap or a stroker rebuild if I can swing it. I have a friend that layed off right now who has the know how to do it. Time to start looking for a donor. ANy sugestions or rebuild kits stroker and standard?