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RoadLife · 03-12-2019, 08:55 PM

318 motor with three speed transmission
replaced just about everything ON the motor.
was driving funny the alt gauge was bouncing and he started to drive rough acting like it was gonna cut off and luckily got to a safe spot to park him after i cut him off tho he started leaking coolant from one of the hoses on the top of the motor.. water pump was okay...
does anyone have any clue what i’m dealing with ?
my temp and gas gauge don’t work. seemed like i was overheating ... so do i replace the thermostat ?
regardless long story short i can fix this issue and keep pushin or i can swap the motor out and try an get a four speed...
any good crate motors for decent price i should check into?

A32Deuce · 03-12-2019, 09:08 PM

You could have water spray onto your distributor or electronic ignition box or the alternator. Get the leak fixed then check your electrical connections and the inside of the distributor cap. Then see how it is.

IBTripping · 03-13-2019, 12:12 AM

It possible that a bad thermostat contributed to causing the leak. Heat built up causing increased pressure. A new thermostat is a cheap maintenance item.

monte433 · 03-13-2019, 08:27 AM

Make sure the alternator belt is still on and tight enough that it's not slipping

**Spdracr39** · 03-13-2019, 08:46 AM

And in the process I would fix the temp gauge even if it was an aftermarket rigged up one. It could prevent you from needing to have the crate motor discussion in the future.

RoadLife · 03-13-2019, 09:10 AM

that was the first thing i checked

Bob_C · 03-13-2019, 09:20 AM

On the back of the instrument cluster there's a voltage limiter that can fail, along with the printed circuit .....

tbos1958 · 03-13-2019, 11:06 AM

I had an old dodge van that had gauge issues and it turned out to be a bad chassis ground. Trace it down and make sure it’s a good clean connection. If it is then you have at least ruled it out. On that same van I also replaced the radiator, thermostat, water pump, and alternator. All at different times and none of them were associated with the funky gauge issue.

Superburban · 03-13-2019, 11:18 AM

The old ammeters did not fare well back in the 70's, and do not age well.

All the power (Except for headlights, and starter), goes through the ammeter, when they start melting, you will get all kinds on intermittent issues like you describe.

Read these.

Catalog

https://www.allpar.com/history/mopar/electrical.html

keymastr · 03-13-2019, 01:13 PM

1977 should be a carbureted engine. If the fuel pump is weak or filter is plugged or it is just tuned too lean then it can make it run hot and overheat.

It can also be from a plugged radiator or a radiator cap that does not hold pressure or from a blown head gasket. When cooled down open the radiator cap, start the engine and look for bubbles. Also look for coolant leaks. If you don't see leaks but coolant keeps dropping it may be being pushed into the engine and burned.

Unless the motorhome is extremely nice for it's age you can probably find a newer, nicer one for less than the cost of a new crate engine.

I had a 1977 Tradesman motorhome new that had a 440 engine that was much better suited to pushing that much weight. If you trade for another or want to swap engines that is the way I would go.

RoadLife · 03-18-2019, 09:45 AM

so i replaces the thermostat and it seems to be at running temp okay with no issues haven’t driven it yet but sat idle omg for a min . no leaks or anything so thanks for everyone’s input

IBTripping · 03-18-2019, 09:10 PM

Quote:

Originally Posted by RoadLife

so i replaces the thermostat and it seems to be at running temp okay with no issues haven’t driven it yet but sat idle omg for a min . no leaks or anything so thanks for everyone’s input

Glad it was an easy fix. Thanks for updating us.

Terry78 · 03-19-2019, 12:15 AM

The famous Dodge 318 (in this case) is most
Likely a 360. Same block different bigger heads
Bigger valves and ports. The best bet is to find
An instrument cluster at a wrecking yard and try that. If that coach sat in the sun for a few years
Then the plastics inside are probably weather
fried. Sun and heat can do damage to older
clusters like yours. As for the leak check and
see if you have a short hose BEHIND the water
pump. It would be about 2 inches long running
To the intake manifold. These are often overlooked during maintenance. Take it to a shop and get a pressure test on the radiator.
Best of luck.