Originally Posted By: JohnBrowning
The trick is changing the fluids for the transmission and diff's and such on a regular basis and much sooner then OEM's recommend.
I believe this is very true, I believe many people ignor diffs, auto transmissions and standard chasis lube but know to take there car every x miles to get the oil chnaged.
I have a few trucks and all have over 180k on them as daily drivers.
93 c1500 2wd pickup, 4.3L
Mile 0-45k it was a work truck for a construction company. I dont know how it was treated, but it didnt appear abused. They ran 15w40 in it always and it was a PA truck. My dad bought it and ran it up to 97k miles and he also ran HDEO pennzoil with 3 to 4 k mile oci . So the truck had HDEO in it from day one to 97k miles at this point, winters included. I bought the truck from him and continued the 15w40 oil changes at about 3k miles. I lived in NC so weather was a bit milder than the truck was used too. I used many oils over the years in that truck, winters i would use 10w30 ST or HDEO just depended on the season and my mood. As the truck got older, i could hear a slight lower engine knock on cold startups. After obsessing over oil for the last year, i have switched it to 5 or 10w30 as i am convinced that the way i use it dont warrant the HDEO and actually is just unnecessarly hard on it upon start ups. Anyway the years that i had it, it has been used very lightly, interstate driving to college and stuff for 40 mins at a clip ect. A few times i pushed the little 4.3 pretty hard, towing cars or trailers with 4 atvs on it thru the mts. Anyway the engine is still in very good shape. Oil consumption is about a qt per 3k miles, compression is still within specs, i believe they were all at 180 ish and one was about 1 psi lower as of a year ago. Maybe the numbers were 160 and 150 cant remember now but i think it was 180. Lower engine knock is still there upon cold starts. It is very light but noticable. So the truck is now at 215k miles and still in pretty good shape. I have replaced the intake manifold gasket and valve stem seals.
01 chevy blazer, 4.3
mobil1 5w30 forever on 5 to 8 k oil changes, since new here in nc and the engine was flawless up to 170k miles when the leaking IMG caused the engine to sludge up and a lifter to start sticking. After changing the gasket and running a few ST 10w30 flushes and a HDEO flush, it is now back on its synthetic only PP not M1, high iron stories got me to switch. Seems to be doing good now and has 180k miles on it. I have other issues with the truck but not engine.
Now for the engine that ran until failure.
99 suburban, 350
I bought this truck with 167k miles, and the body was in great shape and everything seemed to be okay with it. Well when i got it home, i changed the rear diff fluid and it come out jet black and there was a flim of sludge covering everything in the diff cavity. The front diff fluid came out like chocolate milk mixed with cottage cheese. Well seeing this, i figured i would do an oil change and when i did, i notice that the oil that came out, was very very thick. Well i threw some dino 5w30 in there thinking i would do a 1000mile flush or so being everything else appeared to be neglected. Well the truck held about 5psi oil pressue when hot with 5w30 in it. I did two very short runs with dino and changed it to M1 5w30. Not a good idea, within 500 miles it started knocking and another 1k down the road it spun a bearing. Upon taking the engine out to replace it with a rebuilt, i noticed a 1/4 inch hard crusty black stuff all over everything inside. It was apparent this engine was very neglected. So i have had to rebuild the front diff, transfer case and replace the engine. Yea, im not making this up. I would bet that the care that the lubes in that truck got would probably make most bitog guys loose sleep at night.
Stepfater has a chevy work box truck with a 350 in it that now has 320k miles on it in PA. No internal engine work and gets changed with dino between 3 and 5 k miles. Still in use
My cousins S10 with 4.3 gets 10k oil changes in PA with any name brand dino usually castrol. I think the marker is at 140k miles around. This engine has been used very hard at times. When we were younger, he was into car audio competition and they had a SPL Van built that they would haul to different shows. I dont remember the weights, but the van was very heavy as it was full of MDF and batteries and was towed on a HD lowboy trailer. One summer i went to a comp with him in ohio from PA. I almost could not ride in that poor zr2 when we would hit those mt hills. Petal to the floor and that 4.3 would just scream as it pulled probably twice what it was supposed to be pulling. Anyway his dad has it now and it is still going strong.
Anyway that my truck story, All three of my truck are still in service and hopefully will continue to pile on miles because i dont want to buy a new truck anytime soon.