Sorry for the long post, but wanted to give as much info as I could..........
I'm working on a project boat. A 1994 chaparral 18 foot.
I bought this boat with no engine or drive.
I was able to find a used 94 4.3 mercruiser and a GEN II drive with all the plug and play stuff on it.
I installed the engine 2 weeks ago, everything went great, ran good, oil pressure good , temp stayed right above 120 degrees.......
The next day it was hydrolocked, ended up having a cracked block and both heads were cracked......
I had a 1989 4.3 mercruiser engine in my shop, so I decided to install that one to finish out the summer.Sorry, don't have the SN for it, it's missing.
After installing the second engine, I used the circ pump, t-stat housing, manifolds and risers off the first engine since I had no problem with them. They did keep the first engine cool.
Compression is good ( 160 on all cylinders )
new tune up
timing is set
NOW THE PROBLEM:
while running on muffs, using a temp gun,
intake manifold at base of t-stat 118 degrees
top of risers 76 degrees
bottom of exhaust manifolds 95 degrees
inlet hose at power steering cooler 62 degrees ( I have cold spring water )
block at core plug 190 degrees
water pump ( circ pump ) 187 degrees
I removed the t-stat for testing purposes and the results were the same.
I removed the water hose at the power steering pump and checked it. At 1000 RPM for 15 seconds, it got 3 gallons of water.
When I shut the engine off, I can hear and feel water bubbling in the hose going from the t-stat housing to the circ pump, like it's boiling and it is also hot.
My exhaust manifolds and risers are clean with no problems ( that I can see )
Also noticed that the water OUTPUT ( at the drive )is not as much on this engine as it was on the first one.
I'm sure I have blockage somewhere, but am lost on where to begin.
Any chance a bad head gasket could cause this? even though compression test was good.....
I'm sure you folks can throw idea my way that I would never think of.
thanks in advance,
wncrjb
I'm working on a project boat. A 1994 chaparral 18 foot.
I bought this boat with no engine or drive.
I was able to find a used 94 4.3 mercruiser and a GEN II drive with all the plug and play stuff on it.
I installed the engine 2 weeks ago, everything went great, ran good, oil pressure good , temp stayed right above 120 degrees.......
The next day it was hydrolocked, ended up having a cracked block and both heads were cracked......
I had a 1989 4.3 mercruiser engine in my shop, so I decided to install that one to finish out the summer.Sorry, don't have the SN for it, it's missing.
After installing the second engine, I used the circ pump, t-stat housing, manifolds and risers off the first engine since I had no problem with them. They did keep the first engine cool.
Compression is good ( 160 on all cylinders )
new tune up
timing is set
NOW THE PROBLEM:
while running on muffs, using a temp gun,
intake manifold at base of t-stat 118 degrees
top of risers 76 degrees
bottom of exhaust manifolds 95 degrees
inlet hose at power steering cooler 62 degrees ( I have cold spring water )
block at core plug 190 degrees
water pump ( circ pump ) 187 degrees
I removed the t-stat for testing purposes and the results were the same.
I removed the water hose at the power steering pump and checked it. At 1000 RPM for 15 seconds, it got 3 gallons of water.
When I shut the engine off, I can hear and feel water bubbling in the hose going from the t-stat housing to the circ pump, like it's boiling and it is also hot.
My exhaust manifolds and risers are clean with no problems ( that I can see )
Also noticed that the water OUTPUT ( at the drive )is not as much on this engine as it was on the first one.
I'm sure I have blockage somewhere, but am lost on where to begin.
Any chance a bad head gasket could cause this? even though compression test was good.....
I'm sure you folks can throw idea my way that I would never think of.
thanks in advance,
wncrjb
