I was checking the timing the other day and when i started to check the timing the engine knocked for a few seconds then quit. Starting cold theirs no knock but sometimes it will knock with a warm start i went from 10-40 to 5-30 oil and its still doing it. i changed the timing chain and oil pump with engbldr parts about 4k miles ago the motor has 141k miles, the truck has been sitting for about 3 months because of an accident.

 

If it did it sometimes with 10w oil and does it all the time with 5w oil, the thinner oil is the problem. You can easily run 20wX oil down to 32F, 10wX down to about 15F.
I'm in Washington now and am running 20w50 in my truck and no problems with oil pressure even when it's hit 5F.
Consider that.

 

I thought the thinner might help but we have had several single digit mornings in the last few weeks. i run 0-30 in my car all year with no issues.

 

I'm guessing your car with the 0w30 all year 'round is not the truck with 10w40, right?
all vehicles are not built the same so don't assume that since you can run 0w30 in the car without problems, you can run the same in your truck.

I'm not trying to chastise you or anything like that, just saying that different vehicles are different and as such don't require the same oils.

You're getting knock in the truck because the oil is too thin and drains back to the oil pan.

 

Running a thinner oil will help, somewhat, with mileage, particularly with a cold engine but is it going to save enough fuel to pay for rebuilding the engine when the engine bearings and such go, caused by rod knocks and thin oil?

 

i did run 0-30 in the truck but it started leaking, but the where valves where a lot quieter now it just gets whatever on sale.

 

Listen to Abe dude. He knows his stuff. 20W50 is a perfect viscosity for the 22RE.

 

shhh...
I didn't say 20w50 is the perfect viscosity. I only said that if it knocked more with 5w than it did with 10w, the oil is probably the problem, and that I am running 20w in sub-freezing weather without problems. Every engine is different and there is no singular solution.

 

For real, I've been running 5w30 synthetic in my Pickup for the last 62k miles with zero issues, year round. I bought the truck w/ 100k on it, it's now got 162k.

 

It doesn't really get that cold in Oklahoma so I think trying some 20W50 might help in your case. Here is Mass it's cold as hell right now and I wouldn't want to run anything more than 10W30 here in the winter, which is what I use year round and my 22re likes it

 

Could the knock sensor cause a knock, bad oil pump. has anybody ever had a similar problem

 

I'm getting code 25 which is AIR/FUEL RATIO LEAN INDICATOR--LEAN SIGNAL SENT TO ECU FROM O2 SENSOR

--INJECTOR FAULT(S)

--FUEL PRESSURE

--OXYGEN SENSOR

--AIRFLOW METER OR MAP SENSOR

--IGNITION

--ECU

i have replaced the 02 sensor (denso) and the maf recently. So what could cause a random warm start knock?

 

any ideas?

 

Get a noid light and a mechanic's stethoscope and check that your injectors are all firing. Should sound like a steady clicking. The noid light will blink if they're getting signal. That will let you know several things.

1) noid light = blinking = injectors getting power
2) noid light /= blinking = injectors NOT getting power
3) Injectors = clicking = operating normally (assuming the clicking is consistent and quick)
4) Injectors = NOT clicking = faulty injector(s) OR bad connection.

Get a fuel pressure gauge and hook it up to the fuel rail. Jump +B and FP in the diagnostic block w/ the ignition ON to run the fuel pump. Check rail pressure. Start truck, rev motor. As engine RPM increases, fuel pressure should also increase. A decrease in fuel pressure could be a dying pump, or a VERY clogged fuel filter. (first hand experience with the filter deal)

Test the VAFM per the FSM to make sure it's within spec.

 

i was searching Google and this sounds promising "Some pumps will only fail after warming up, so they appear to work fine after they have "rested" for a while. This is the sign of a dying fuel pump motor" as anyone ever had a similar problem?

 

Jump +B and FP in the diagnostic block while checking fuel pressure, or with the motor running and find out for yourself!

 

I just bought an 88 4runner 22re, and when its sat for more than 5 minutes, and you start it it knocks about 5 times, if it hasnt sat for long, it doesnt do it. This is caused from the oil draining back down correct? Im hoping the 20w50 oil will help.

 

Do you know for sure whether your "knocking" is a rod knock caused by loose bearings (which oil weight would affect) or detonation (pinging) caused possibly by mixture too lean or ignition too advanced or other causes?

A rod knock is a lower pitched sound, and is more regular, whereas pinging is higher pitched and more sporadic. If you're not certain, drive to a shop that has a good reputation and ask a mechanic to listen to it.

 

I know the difference between pinging and a rod knock. the more and more i think about i think its fuel related the problem. cold start is fine let it warm up turn it off for a 5-10 minutes and it knocks. I'm go to try to test the fuel pressure today.

 

Okaaay...

I guess my point is, which is it? Your original post and the ones immediately after are talking about rod knocks, and oil weight. Now you're talking about pinging and knock sensor and fuel. They're different problems with different causes and different solutions.