1977 ford 302 model 888

[scubadoo73]

I am over heating
at idle and idle in gear I'm good about 140 f when i hit the throttle she slowly climbs to about 220f i drop the throttle and it will hold that temp 220f
work done new impeller, new water pump, new shutters, elbows and risers are all cleaned and good condition, new thermostat 140f have manifolds off and they are all clear
waterline from impeller to thermostat is clear have poped frost plugs and they are all clear of crap
any suggestions

 

[mrflip2]

Re: 1977 ford 302 model 888

I am over heating
at idle and idle in gear I'm good about 140 f when i hit the throttle she slowly climbs to about 220f i drop the throttle and it will hold that temp 220f
work done new impeller, new water pump, new shutters, elbows and risers are all cleaned and good condition, new thermostat 140f have manifolds off and they are all clear
waterline from impeller to thermostat is clear have poped frost plugs and they are all clear of crap
any suggestions

Here is what I tried when this happened to mine and it fixed it
checked hose from outdrive to thermostat should push out two feet when running at 1000 rpm (dont forget to make sure muffs are covering holes in outdrive.) Didn't have great water pressure redid impeller found tiny tiny tiny piece of old impeller rechecked good water pressure then.
If good there remove or loosen drain plugs and see if water is reaching that point.
all freeze plugs back in??
Do you have water coming out of prop and outdrive while running?
i know that the impeller was the hardest for me thought I had it twice but those tiny peices drove me nuts
Good Luck

 

[cr2k]

Re: 1977 ford 302 model 888

ALWAYS find all the old pieces of the impeller, you never know where they might end up. Is your thermostat working?
You could have a flapper stuck in your exhaust.

 

[scubadoo73]

Re: 1977 ford 302 model 888

Flappers all good used an inspection camera opend np took lower unit off again put hose dirct to hose in upper unit same amout of water came out as went inno kink all freeze plugs are in

 

[scubadoo73]

Re: 1977 ford 302 model 888

Thermostat good

 

[muskyfins]

Re: 1977 ford 302 model 888

I'm no expert but double check the routing of the hoses.. the top hose from the thermostat should be the top hose on the back of the manifold.. also how is the impeller housing?. If it is cracked or warped it will let exhaust into your cooling system

 

[scubadoo73]

Re: 1977 ford 302 model 888

I put a temp probe on both manifolds(laser) starbord reads 200 and port is 120 so starbord isn't cooling but I have water flow thru the block not sure where to look now all hoses are routed properly and are clear of obstructios

 

[achris]

Re: 1977 ford 302 model 888

http://forums.iboats.com/showthread.php?t=556903&p=3825409&viewfull=1#post3825409

 

[scubadoo73]

Re: 1977 ford 302 model 888

Achris that has been chjecked and all is good

 

[achris]

Re: 1977 ford 302 model 888

Achris that has been chjecked and all is good

Excellent... I had to mention it, it's one of those things people overlook... and can bite you in the ....backside quite easily...

 

[scubadoo73]

Re: 1977 ford 302 model 888

Iam starting to wonder if I have a bad piston any thoughts

 

[scubadoo73]

Re: 1977 ford 302 model 888

Update the issue has been resolved pulled all frost plugs from starboard side again and found a little piece of impeller also more crap. Put plugs back in took it to the lake and when it started to heat up again I increased the fast idle to 2000 rpms then to 3000 and that cleared the rest of the blockage. Thanks for all the advice. This motor was a case of neglect from the last owner.
Have a safe and happy boatong season all.

 

[Eric 3.7LX Alpha 1]

Where are the water shutters located on a 77 302 888 mercruiser...is it at the bottom of y pipe or in the exhaust exits...1 or 2 shutters....I have a rumbling sound at idle and growling when taking off...put new gimbal bearing in and u joints new lube , but growls bad taking off...need help...thx

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