89 chevy truck & MOS

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Soon I will be adding MOS to oil of an 1989 Chevy truck 1/2 ton, it is the 5.7 liter engine with well over 200k miles on it. This truck is largely now only used when we get a lot of snow fall during my commutes. So it can sit around for a long time except that I do try and start and run it every 2 weeks and slosh the fuel around in it. Obviously it likely needs heads reworked, but i thought I would use some MOS and report my observations. Once again only one persons honest and unscientific report. YMMV Below is a video, my son shot for me while I fired it up,,, it had been sitting for about 2 weeks. In the video, you'll hear me ask my son if he's ready and he say's yeah.. I crank and start it and you'll see the smoke. [img]http://i1026.photobucket.com/albums/y330/jcxx75/th_20141214_125444.mp4[/img] Some time later this week, i plan to add the MOS, drive it to work, which will get it nice and warm as required by the instructions on the can of MOS. Will report back at some later date as I get a chance to make some observations. on edit: forgot to mention,,,I have pennzoil 5w-30 HM oil in it for about 500 miles more or less.
 
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My bet is MOS will stop that smoke. It is good stuff. It has reduced the RMS leak on my Jeep 4.0 to just a few drops after shut off. Thanks for posting and looking forward to the results. It might take up to 500 miles, so give it time.
 

John_Conrad

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thanks for posting your observations. for me it will likely be next summer before I put teh 500 miles on the pickup, now that having been said, we'll probably go right into a snow making winter! however, my son is now licensed to drive and he will likely increase the use of this older truck of ours to get around for his school activities.
 
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My dad had a 89 chev truck, same engine. Start up smoke, but no use during running indicated valve stem seals, a common issue with that era 5.7. It is an easy fix, and will stop most start up smoke.
 

John_Conrad

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that's what i figured, but some how i never get the time to do it... someday perhaps i'll get around to it. in the mean time i thought i'd play around with the additives.
 

John_Conrad

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thanks for posting. I do believe the HM oils have slowed it down a bit, but not entirely. I ran some Castrol 20W-50 HM in it starting last winter and into most of this summer and it has not eliminated it. It may just need replaced but I thougth i would run the MOS and give it a chance. I didn't like the 20W-50 in the winter, it's just too thick, the oil pressure let's me know and the cranking is a little slower and a bit more noise in the engine at start up than i like especially when it's below 0 degrees. I do like the idea of a 10W-30 or a 15W-40. Your point is well taken. I went with the 5w-30 because my research showed it should be as good as todays 10w-30(hope this don't open a can of worms). And my oil pressure gauge shows as good oil pressure with the 5w-30 for our winter temps so far. So i am one step ahead of you and have a 15W-40 in hand. I went with the super tech brand, just for a trial run. What other 15w-40 oils might I try? Besides delo and rotella T? ON EDIT: i guess i could also look for a thick 10W30, right?
 
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John_Conrad

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Of course, if I have success with the MOS and the 5w30, and still maintain good oil pressure even through the summer, I will look no more. So for now I need to give this a chance to work, but I have second base covered if I need to throw there!!!
 
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I had a 1990 Blazer with the same engine. Same start up smoke from the valve guide seals. I just left it and ran the cheap WM ST 10w30 HM oil. Not worth the fix in my opinion.
 

John_Conrad

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thanks for posting, i figured that was the problem, but I thought if I was going to take the head off I would have them all replaced which is what I meant rework the head. I have never done seals myself but I could look into it and learn, i would consider myself an above average shade tree mechanic, having learned everything by reading and experience. I have done engine removal and replacement in an old '78 chevy and taken heads and intakes off etc. how can I identify if it is only one seal or more that may be bad? I know for sure the #1 plug gets oil fouled a bit, but I have not checked plugs in a while. thanks for your help p.s. on edit: i do have tool to compress spring and remove valve, but don't remember actually doing it!
 
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John_Conrad

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Originally Posted By: sw99
I had a 1990 Blazer with the same engine. Same start up smoke from the valve guide seals. I just left it and ran the cheap WM ST 10w30 HM oil. Not worth the fix in my opinion.
if i can get it slowed down with the HM oil and the MOS, i may not worry about it either. But if i find the time some day, this would be a great father and son project as my boy is going to start driving this old truck of mine soon. the puff of smoke personally didn't bother me, even when people are around when I go to the city.LOL And it has slowed down a bit with the HM oil. It seemed worse in the past before the HM oil, especially when the wind picked it up!!
 
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Originally Posted By: John_Conrad
thanks for posting, i figured that was the problem, but I thought if I was going to take the head off I would have them all replaced which is what I meant rework the head. I have never done seals myself but I could look into it and learn, i would consider myself an above average shade tree mechanic, having learned everything by reading and experience. I have done engine removal and replacement in an old '78 chevy and taken heads and intakes off etc. how can I identify if it is only one seal or more that may be bad? I know for sure the #1 plug gets oil fouled a bit, but I have not checked plugs in a while. thanks for your help p.s. on edit: i do have tool to compress spring and remove valve, but don't remember actually doing it!
Heads can stay on, fill cyl with comp. air at TDC, remove keepers, spring,old seals, replace, move on to next cyl. Just do them all..
 

John_Conrad

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thanks, i was aware of or had read some where about the compressed air procedure. concerns are: 1. i would need to buy adaptor thingy to screw into plug hole and 2. if my compressor would hold it(and i'll have to look at it's capacity later tonight to tell you which craftsman model it is and how many gallon)
 
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I use an old compression tester attached to my air hose screws in the plug threads, And not much air pressure is required, just enough to keep the valves closed to much and it will roll the motor off of TDC,i think I use 90psi or in that area, you don't want a valve to drop in that will ruin your day.
 
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The adapter is cheap and you can use any air compressor, but all the valves have to be closed of course. You also need to regulate the maximum pressure in the cylinder, it doesn't take a lot. I've done it a ton of times and it works well. I like it better than stuffing rope or string into the cylinder.
Originally Posted By: John_Conrad
thanks, i was aware of or had read some where about the compressed air procedure. concerns are: 1. i would need to buy adapter thingy to screw into plug hole and 2. if my compressor would hold it(and I'll have to look at it's capacity later tonight to tell you which craftsman model it is and how many gallon)
 

John_Conrad

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there was a southerly wind blowing, which would be out of the left on the video, and that may have kept it from blowing out like i'm used to seeing it!, other wise the pennzoil HM oil I am using in it now may have slowed it down just a bit. so i'm hoping the MOS will possibly do a little more on it. We will see... I drove the truck to work this morning as we had about a 3" snow fall and i'd rather have the 4X4 just in case on my commute. So i was able to add the MOS into the crankcase this morning before I began my trek. The drive usually takes me about 35 minutes, but this morning it was over an hour as the road I drive on for about 35 miles is a "secondary" route and does not get bladed until later in the day. That should've got the oil and additive nice and hot as required by instructions on the can. I wish i had shot a video of it this past summer when it was really an eye sore, especially when I parked next to people at the grocery store!
 
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