98 volvo 5.7 GLI Overheat conditon

I'm still stuck on the "no circulating water pump" issue. That makes no sense.

Does this picture look like the engine you're working on?

http://tinyurl.com/Volvo5-7

If so, then the raw water pump is down low on the far left of the picture (would be the starboard side of the engine in the boat), and the circulating pump is behind the middle pulley that sits directly above the crankshaft.

You'll notice that the belt that drives the raw water pump does NOT drive the circulating water pump pulley. The circulating water pump is driven by both the alternator and power steering belts. And this pump is just as important as the raw water pump.

If the other mechanic said he found a piece of the raw water impeller in the T-stat housing, there might be more debris inside the circulating water pump housing. I'd at least pull the hoses and look closely before trying anything else...

Adam
 
quote:
Originally posted by Buffo

I'm still stuck on the "no circulating water pump" issue. That makes no sense.

Does this picture look like the engine you're working on?

http://tinyurl.com/Volvo5-7

If so, then the raw water pump is down low on the far left of the picture (would be the starboard side of the engine in the boat), and the circulating pump is behind the middle pulley that sits directly above the crankshaft.

You'll notice that the belt that drives the raw water pump does NOT drive the circulating water pump pulley. The circulating water pump is driven by both the alternator and power steering belts. And this pump is just as important as the raw water pump.

If the other mechanic said he found a piece of the raw water impeller in the T-stat housing, there might be more debris inside the circulating water pump housing. I'd at least pull the hoses and look closely before trying anything else...

Adam

Click to expand...


I'm not sure where you got the info that there is no circulating pump, of course the pump is behind the center pulley, it has been there on every gm engine since the v8 engine was designed.
 
as if this was not bad enough, i installed the thermostat & although it seems to run a bit cooler, is still climbs pretty high. now the latest: the boat has a constant stalling problem, which was there prior but not as constant as it is now, now it is not running more than is is running. i have checked the fuel pumps & i am not sure i am getting enough fuel pressure. the shreadder valve on the fuel line is reading 14psi, the schreader on the rear fuel pump assy is ony 10 psi, i have read that i should have 29psi . the boat has throttle body injection. i have read about the black paint chips in the screens but i believe that is on the newer EFI models, can anyone confirm?
also which pump is which, high presusre & low?
one pump is in front above the water separator & 1 is in the back of the motor on top of some sort of box, also were the shredder valve is.
does this engine have a pressure regulator?
where are the screens located that get clogged?
the rear pump got brutally hot at 1 point but cooled down shortly after. the IR gun read over 150 degrees.
 
quote:
I'm not sure where you got the info that there is no circulating pump
Click to expand...


From your post on June 27th, after both D. Andrews and I asked you about the circulating pump, you replied:
quote:
the RWP on the boat runs off of a pulley, & not off of the crank as pictured in the PDF.
Click to expand...

I thought you might be confusing the two, since none of the pumps (raw water or circulating) run "off the crank". They both run on separate pulleys that are belt-driven from the harmonic balancer (which is mounted on the crank). However, the circulating pump has two belts which are shared by the power steering pump and the alternator, while the RWP has it's own belt that only passes over an idler before returning to the balancer.

Regardless, since you found shredded bits of the RWP impeller elsewhere in the cooling system, I suggest pulling the hose on the circulating pump to check the housing for debris.

Adam
 
quote:
Originally posted by Buffo

quote:
I'm not sure where you got the info that there is no circulating pump
Click to expand...


From your post on June 27th, after both D. Andrews and I asked you about the circulating pump, you replied:
quote:
the RWP on the boat runs off of a pulley, & not off of the crank as pictured in the PDF.
Click to expand...

I thought you might be confusing the two, since none of the pumps (raw water or circulating) run "off the crank". They both run on separate pulleys that are belt-driven from the harmonic balancer (which is mounted on the crank). However, the circulating pump has two belts which are shared by the power steering pump and the alternator, while the RWP has it's own belt that only passes over an idler before returning to the balancer.

Regardless, since you found shredded bits of the RWP impeller elsewhere in the cooling system, I suggest pulling the hose on the circulating pump to check the housing for debris.

Adam

Click to expand...
 
i already pulled the hoses & found nothing. as i stated in my earlier comment, the RWP runs off of the crank pulley by means of a belt, the PDF diagnostic info shows the pump running off of tghe crank directly. no big deal, the results are the same.
 
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