ok to swartlkk i would take a video of the sound but being i live and park in front of a very busy street i dout you would hear it. i will try to get it anyways. engine sounds healthy, i can rev to 4k and no knock sputter or anything

and to kristoph30 this is the second time ive heard this knock, it is not loud, there is no water in the oil and vis versa, with stat in i can smell alittle burning coolant but am not leaking anywere, and also not loosing any as i can tell, each time i check it it has pressure and is full to the cap, and i have no coolant in the res so coolant is still full from the rad, i dont want a money pit as my sonoma has costed me enough so far. i need a daily driver, i do not abuse it, never rev over 3k and usually change the oil every 2k instead of 3 cause i think it helps.

any more info would be great, also if the engine does give me the finger what would be the best option? rebuild? or get a junker engine from a dismanteler?

and honestly at this point kristoph30 i have no choice but to fix it, have no funds to find another for another truck at $2500+, and i dont like public transportation. being it couldnt take me even close to my job location.

and if posible can you explain in lamen turms what exsessive bearing clearance means?

 

There are two things that could be occurring here.

1) Excessive bearing clearance is one of them. This is where the clearance between the connecting rod bearings and the crank journals and/or between the crank and the crank bearings in the block gets too large. Both can cause knocking noises, but typically it is the rod bearings that wear out sooner than the crank bearings if that is what happened.

2) Piston slap. Piston slap typically occurs on a cold motor and only lasts for anywhere from a few seconds to a minute worth of actual operation (engine under load). Piston slap occurs because the pistons expand more than the engine block and if tolerances are too far apart between the piston cold OD and the cylinder bore cold ID, the piston will make a knocking noise as it traverses past the top & bottom of its stroke.

If you can find someplace quiet to take the video or go out early in the morning or something like that, it would help us get you to the root of the problem.

 

well i am a night owl and it gets quiet at about 2am so ill take a video then and hopfully but then again hopfully wont make the noise. how your making it sound is more like piston slap. i started it and it knocked for seconds 5 seconds after sound stoped i drove it around the corner to a closer spot to my building with no knocking at all.

and once again thank all your guys for your help and i know i might keep rambling on about problems but thats just my paranoia kicking in. ive never been stranded in one of my vehicles and this blazer better not be the first time.

and last but not least would switching to synthetic oil maybe help my problem or at least delay it?

 

Stick with regular old conventional.

 

so stick with conventional should i drop from 10w40 to 5w30?

 

Sorry didnt get back sooner. Thanks swartlkk for jumping in about the bearing clearance. You brought up a good point about piston slap. That one slipped my mind.

If it was mine. Which it isnt, I dont know what the condition of it is or what you paid. I would change the oil. conventional, synthetic, anything. But I would go with at least 15w40 since youre in CA. I am assuming it doesnt get very cold there. I like rotella t. It is for diesel motors. If anyone else has a good reason not to use it, Please speak up. It id designed for compression ignition engines. It has a "CD" designation on the API seal on the bottle. If you have a bearing issue, it might help. wont hurt in my opinion. If it is piston slap, it probably wont help.

I would drive it like a grandma if you really want it to last. Put the stat in and get it as close to stock as normal.. BTW - there is supposed to be coolant in the res! In between the hot and cold mark. If you smell coolant. there is a leak. Fact. Sorry. Find it and decide if youre going to fix it or milk it a lil longer. As for the fuel pressure issue, I would start with the pump and see what happens. I wouldnt replace everything you mentioned unless you know the intake is leaking coolant and you find out the spider and FPR are really bad. If money really is tight, only repair the bare minimum.

Everyday that you go out to the truck to drive it, speak quietly and nice to it. When you get home, thank it for getting you home safe. Sounds corny, but if thats the attitude you have when you drive it, it will last alot longer.

Its been a long day! LOL!

 

Not with a knock. 5w is like water. If the knock is being caused by excessive bearing clearances in the bottom end of the engine, 5w isn't going to help anything.

I'd move up to something like Rotella-T 15w-40, or any type of 20w-50. Like I said earlier, I'm running 20w-50 in my Blazer, and she doesn't seem to care one bit. Here's the general rule of thumb: Thicker oils mask bottom end noise (main and rod bearings). Thinner oils mask top end noise (lifters). If I were you, I'd go thicker. Rotella 15w-40 or any name brand 20w-50. See if the noise returns.

I'm kind of wondering though...what does your oil pressure gauge read right after you start it? Does it sit on 0 for a couple of seconds, or does it build upright away? If it builds right away, I'm wondering if the guts in your cat aren't rattling around.

Get that video and post it up.

You posted while I was writing LOL!

 

pressure comes right up, ive loooked at the cat and had my friend reving the engine alittle while i see if it is getting cherry colored. i did just pass smog, and it passed with flying colors, cat dosnt look real old actually looks kinda new, no black or white smoke coming out of the muffler, but then again when water was in my oil pan in the sonoma there was no white smoke or any change either. oil and water just started coming out every orifice it could find besides the exaust

so rotela being for diesels wont harm my engine? and if i use it would my regular wix filter suffice?

also this engine starts first turn always hot or cold

 

Rotella will not harm a thing. Rotella has more detergents and cleaners because it's for diesel engines, and it's also less likely to sludge because it's designed for diesels, and diesel engines run hotter than sh*t.

A lot of Land Rover guys recommend Rotella in the Rover 3.9L V8 because they also run extremely hot.

Your wix filter will be fine too.

 

this is a video of the knocking sound, you might not be able to hear it as there is alot of cars going by. i will upload another if needed, i can hear the knocking and right after the first rev u hear tapping. but the sound went away after about 6 seconds

COLD START after a day and a half of sitting

YouTube - ‪2011-06-08_22-32-27_262.3gp‬‏