Enlighten me...how does running without a thermostat lead to overheating? I would think that unless there's some other problem with the cooling system the engine would be running under temp and get poor gas mileage.

 

What brand oil filter are you using? A lot of the cheaper filters on the market do not have an anti-drainback valve, so all the oil flows off the bearings when you shut the engine off. A filter with an anti-drainback valve is highly recommended.

Running without a thermostat can lead to all the previously mentioned problems, and will also promote sludge build up in the engine. It would be a good idea to install a thermostat.

 

20w-50 is ok for the hot summer cause the oil will stay thin enough, but come winter, get it out of the engine...not good for winter cold weather..

 

That's a load of malarkey...what about synthetic blend oils like MaxLife?

 

Thank you 01 blackbeauty for trying to clear up my description about the no thermo to engine failures..back in the day people usd to leave out the thermo to get better heat in the car in the winter, until,they had frozen engin blocks, lololol

 

im running with a WIX brand oil filter which i was told is equivalent to a K&N, i only used K&N oil filters b4 i was told this and the 20w50 oil is probably why when i rolled my sonoma after hiting a patch of black ice the engine ran but all the rad collant was going into my oil pan. since then ive been really carefull on how the engines sound. just would like to get rid of this knock being i am limited on funds and need my blazer being the sonoma is still out of commision atm.

and about the thermostat not being in i do get crappy gas millage and also the temp usually dosnt get past the 2/5 mark on the temp gauge. if its cold it will stay at about 130

P.S i live in southern california were it dosnt drop under 30degs.

 

WIX is a good filter and does have an anti-drainback valve. The knock could be excessive bearing clearance due to high mileage. 5/30 and 10/30 oil is what is recommended for the 4.3 - I would stick with either one of those. Put a 195 thermostat in and the engine will be more efficient and get better mileage. A 50/50 mixture of water/antifreeze will help prevent it from running too hot and will promote even heat distribution throughout the engine block.

 

so would i be able to change from reg oil to synthetic? maybe lower W would get to the pistons and bearings quicker? and how long can i drive it like this b4 it says **** you and leaves me stranded in the middle of god knows where?

 

To the OP, is there any way that you could take a video of the noise you are hearing. So far, I agree with everything that 2002XTREME has stated except for the comment about synthetic oil. But lets not get into that here.

Running without a thermostat can lead to overheating by not allowing sufficient time for the coolant to stay in the radiator where it gets cooled. Add to that higher outside temperatures and the radiator is performing less efficiently than it would if it were cold out. Initially, and if only run for short trips, your thoughts would be true. The system wouldn't saturate in terms of temperature and the end result would be that the engine would likely not overheat, but would remain in fuel enrichment mode where fuel mileage, etc would suffer.

 

You have excess bearing clearance. I would stop all the work you have planned on the truck (Fuel pump, FPR and intake gasket) and sit back and take a deep breath and come up with a plan. You have a coolant leak, fuel and drivability issues, now an engine knock. You dont know what the history is of the truck since you bought it at auction.

It could be a money pit, or it could be the most reliable vehicle you will ever own. You need to decide if its worth the time and money you have already put into it.

Just my humble opinion.

I also agree with 2002xtreme....ESPECIALLY the woman remark!