Exhaust manifold is hot to the touch

[holorinhal]

I have an 81 260 hp/ 5.7 mercruiser. The temp acording to the gauge runs around 160- 170, however the manifolds are hot to the touch. I have been told that the manifolds should feel cool and be able to keep Your hand on them. I s this true or is it normal for the Manifold to feel hot?

 

[jerryjerry05]

Re: Exhaust manifold is hot to the touch

On the hose or in the water? Hose is not enough water.
The manifold/riser should be warm.Not so hot it's that you can't hold on.
If it's not overheating then the steps.Change the waterpump impeller.Check the housing and wearplate needs to be smooth no deep grooves.
Thermostat and housing .Then the riser/manifold.How old are they?They can last 20 yr or 10.Take the rubber boot off and check for corrosion on the end of the riser.
Risers are usually the culprit.J

 

[holorinhal]

Re: Exhaust manifold is hot to the touch

On the hose or in the water? Hose is not enough water.
The manifold/riser should be warm.Not so hot it's that you can't hold on.
If it's not overheating then the steps.Change the waterpump impeller.Check the housing and wearplate needs to be smooth no deep grooves.
Thermostat and housing .Then the riser/manifold.How old are they?They can last 20 yr or 10.Take the rubber boot off and check for corrosion on the end of the riser.
Risers are usually the culprit.J

Running on the hose and in the water. The risers are warm. I can hold myhand on the riser, but the manifold itself is hot that I cannot hold My hand on. Water comming out the prop hub is warm that It does not burn Me and I can hold My hand under.