Hello everyone! My 95 4x4 2Dr Blazer has been having some engine issues lately. I've notice a decline of engine power over the last two weeks; the engine has troubles starting also, it will never start on the first turn. I have just checked my coolant, which was leaking a few weeks ago and seems to have stopped since adding some stop leak, the coolant is oily black.



Over the last two days while starting the truck the engine has made an explosive knocking sound, it only happens the once during turning the engine over, once the engine is started it is fine.

I'm far from mechanically inclined, but I've got a feeling in my gut this is far from an easy or cheap fix.

 

flush the cooling system as that stop leak looks like it's doing some nassssty damage to it.

 

oh man! what uber said!

 

btw what did you do? add like triple what you should to it? oh and where's it leaking from? is it leaking in the rad? or on the block? or is it just a line? truthfully the LAST thing you should have done was pump that pollution into your cooling system rather than properly fix/replace the part that was causing a leak! the flush alone, unless you did it yourself, most likely is now going to cost you that money that was once thought saved lol.

further info on that explosive sound plz? like does it turn over, you stop rolling, and you hear a LOUD bang?? or during initial roll does it make a loud sound? could be a loose plug allowing the spark of fuel come thru some and you just hear it louder than you should.

 

Thanks for the responses guys! I will try a coolant flush sometime next weekend.

Uber - Not sure where the leak was. The explosive sound only happened twice, but it was always on the second try of starting the engine. First turn over generally doesn't work on my truck.

 

tbh does it sort of have a bog sound @ the end of the "explosion" ? if so good chance its a backfire or it catching but just on the end of the ignition stroke releasing the pressurized gases a bit more forcefully than naturally aspirated (forced out)

 

It's probably just the stop leak vapor leaving deposits in the coolant tank -Flush that toilet!!! Seriously though, how does it look inside the radiator, under the radiator cap"





These engines(95's in particular) are known for digesting the intake gaskets. I would look there first!

Hope that helps you out!

 

So I finally had a day off to get some work done on this. I was able to drain the system and flush the radiator (wasn't able to hook up a house and do a full system since it was still freezing temps outside). The coolant didn't look as bad as I thought it would. I changed the oil also.

Neither the oil or the radiator had any chunks of debris, which I assume is a good thing. How quickly would the coolant or oil change colors if any of the gaskets were blown?

 

ud notice a leak first i'd think. just check allll around the block for wet spots, touch them n see if its slick n stays that way for a min or 2 (that'd b oil) or goes sticky like as it drys up - if that wipe it clean, drive around for a day or 2 and recheck that spot for the leak again.