s10 either rod knock or valves dying

[VetteOwner]

how the heck can you tell? Whats a good way to test to see what it is?

[imzjustplayin]

either way the engine is trashed... why does it matter? I suppose you could run the engine with the valve cover off and look or get under the car and try to hear the oil pan.. Though if I had this problem, I just would either rebuild or just trash it considering that both problems are serious.

[GasSavers_Erik]

A compression test would tell you if it is a bad valve. A bad intake valve will usually make a popping noise out the air filter. In general, a bad valve will also usually cause a miss at idle.

A rod bearing noise will get worse under load. Heavy (20w-50) oil would make the rod bearing more quiet. Usually you will hear a rod bearing knocking for a second or two at startup (when oil pressure is building) before it gets bad enough to knock all of the time.

Do you have hydraulic lifters? It could just be a collapsed lifter and you are just hearing a huge tick. Use a broom handle to isolate where the noise is coming from (one end to your ear, the other end against the block)

[theholycow]

Where are you located? I have a 1994 S10 2.2L engine that runs great that I'm planning to sell.

[IndyFetch]

Originally Posted by Erik

A compression test would tell you if it is a bad valve. A bad intake valve will usually make a popping noise out the air filter.

I think that may only work for an intake valve... if it is an exhaust valve that is going bad, the popping will be out the tailpipe.

[VetteOwner]

well i prolyl should have gave more info:

its a 1995 chevy s10 2wd 4 banger (2.2L)

for years now and prolly the last 50K miles at startup cold engine it would tick and sound like popcorn being popped, drove great tho, same power, no stumbling.

it would ALWAYS go away (obviously dead of winter would make the tick last longer till the oil warmed up) well its not going away anymore. same power it seems but when im driving in the open i cant hear the tick but if i get near a curb or a wall (drive thru, atm, alleyway) i can hear the sound.

oil psi according to the guage is about 60-80 driving 40 idle and it does change with rpm.

it does have hydraulic roller lifters.

reason i need to know is to replace the lifters, headgasket, head bolts its only going to be ~$170 in parts (i do the labor, ive had another 2.2L torn apart so its easy to do)

if its rod knock im pretty well screwed or have major work that i may not want to do...

even tho the sound is getting worse it starts fine (seems i have to crank it an extra second sometimes tho) runs fine (no stumbling or bogging) still has the same power (can haul 1000lbs of rock still)

heres a video of it this past winter (it was near 0*F on the first start in 4 days)

http://www.youtube.com/watch?v=28IRZ9l2MCE

it used to go away 100% (i know it sounds pretty bad now)

ive always ran 5W30 conventional oil

[GasSavers_Erik]

I think it is more likely a lifter. A small rod knock would likely get pretty quiet as soon as the oil pressure came up (5 seconds after starting) and then might come back when the oil got hot and thin- especially under load.

A sticky lifter would likely take longer to quiet down. Load wouldn't make a difference for a bad lifter and eventually it would tick loudly all of the time if it stopped working completely.

Start it up and try to pull a big trailer or try to start on a hill- in any case, put a load on it and see if the noise gets loader (rod) or stays the same (lifter).

Listening with the broom handle should quickly tell you where the noise is coming from. You have to put the handle against your skull to "hear" it.

I had moderate success with a sticky lifter (chevy 305 v8) substituting 1 quart of ATF for engine oil. The ATF is supposed to have more detergents than engine oil. The lifter was quieter and acted up less than it had been- but it wasn't as good as new.

[bowtieguy]

i'm w/ Erik. i've had several GM vehicles w/ noisy lifters. they never got that bad tho. amsoil 40 weight quieted them down. i've heard about the use of tranny fluid as well.

[VetteOwner]

well i had the local school bus mechanic (friend of the family) take a look at it with this expertise and mechanics stethoscope and he believes its the lifters too for the same reasons listed above, temperature really affects it (thats dead of winter so super thick) summer it goes away ALOT faster and not as loud on startup.

sooo $170 in lifters, headgasket, headbolts and i should be good to go.

I've heard you have to preload lifters when their new before you install them. I've heard of submerging them in oil and slightly pressing on them to get the air out. Is that true?

Also another thing the auto parts store suggested is to have the head magnafluxed for cracks. Its never leaked any coolant and compression is pretty even across them all so would you recommend doing that?

Another question is its pretty inevitable to get coolant in the oil when you remove the head. i literally JUST changed the oil in it 2 days ago. Can I drain the oil and save it to put back in?

I plan to drain the coolant and flush the system anyways but plan to put green back in instead of the dexcool orange (havent had any problems with dexcool but we have a crapload of green antifreeze sitting around the garage) would you guys recommend draining the orange, replacing lifters get it back together, fill radiator with straight water running it and treat it like a regular coolant flush? We usually just drain coolant into buckets, run truck with garden hose till clear water comes out (heat on in the cab) then drain that and refill with 50/50 mix. Do I have to do anything special because Im changing colors?

[GasSavers_JoeBob]

Even if it's a rod knock (which it probably isn't), if the crank shaft is still in good shape (check with a micrometer), it's not that difficult a fix. Just annoying.

Have you tried running something like Rislone through the engine, then changing the oil again? BTW, I wouldn't save the oil in the engine...oil, even now, isn't THAT expensive.

Does the auto parts store have a machine shop attached? That does magnafluxing? If so, they're probably looking for an add-on sale. That said, it wouldn't hurt, and if it did show up a problem...