• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Engine vibes, coolant on the hood...Water pump?

Share this page

Tremelune

Tremelune

Member
Offline
I drove my 1965 Sprite (1098cc motor, I believe) for the first time since September and noticed coolant everywhere under the hood when I stopped for gas. I couldn't tell where it was coming from (the motor is rarely dry of fluids), but there was a splash on the underside of the hood, some spots on the top of starter...

The temp gauge behaved normally until I got back home and left the car idling to try and inspect the noise. It went up near 200 (I think), and the coolant spilled on the motor was starting to smoke, so I turned off the car. That's when I saw the pool of coolant spreading on the floor of my garage.

I also noticed during the drive that the motor had a very pronounced vibration. I couldn't identify it, but it was definitely from the motor, and it went from mild to wild with the revs. I just put a new gear-reduction starter in the car, but I don't think that's related.

My guess is that the cold weather did something to the water pump, and when the car got running again, it gave up the ghost and dumped coolant everywhere (including splashes from the drive belts). How do I confirm it's the water pump? Is this a difficult job?
 
The thing about coolant is that it is usually obvious where it is coming from as it is a pressurized system. Easiest way requires an assistant and perhaps a flashlight. Get it running, and start looking for where it is coming from - has a hose perished? is a connection loose? I had a pinhole and it was stunning how much liquid it could spray. Could also be a frost plug (they also rust I think) There are lots of possibilities but, not many places to look if that makes sense. Another option is to get under the car to see if you can track the drips - look for what is wet.
 
I believe they also make an additive that shows up under a blacklight. You should rinse off the engine bay pretty thoroughly first, and I guess let it dry, so you maybe see where the leak originates. May not leak until hot, too. You could also just start by checking and tightening hose clamps. Sounds like a pretty good leak or spray to get coolant all over the place.
Bill
 
I'll get in there and give the pump a shake, maybe fill it with water and really poke around.

Is there a "good" water pump to put in there, or is it pretty much limited to the one Moss Motors sells for $30? Water pumps usually go 60k miles these days...
 
If you do replace the water pump give it a few spins by hand before putting everything all back together, I found the pump from Moss and VB all hit the inside wall of the water jacket on my 65 1098. It was not much but enough that I removed a little lining so that it spun freely. The new pumps vanes are a little different than the origional. I would fill it back up and ran it before I started replacing things, as mentioned it might just be a hose.

Mark
 
Frank ought to chime in on this. I think there are two different water pumps out there depending on engine. They look like they will both fit but one has clearance issues.
 
There's a "long impeller" pump and a "short impeller" pump. On the long, the impeller (the part that moves the water) sticks out farther. I'm not sure which one the 1098 uses, so I won't speculate.

Don't assume it's a water pump until you're sure. We humans have a natural tendency to expect the worst, but that isn't always what happens. Some problems are simple to solve. Look for the leak and when you find it, go from there. If it is the water pump, it's cheap and easy to replace.

By the way, it's OK to fill it with water just for the time it takes to find the leak. Then, when it's fixed, of course fill it with the correct coolant.
 
I can't see <span style="font-style: italic">exactly</span> where the water is coming from. I think it's coming out of the water pump where the pulley attaches...The car is fine until it reaches operating temperature, then water comes spraying out sideways towards the generator from directly underneath the water pump pulley. I think it's mostly the spinning pulley that "sprays" the water sideways. After a few seconds, it stops spraying. I tried looking up from beneath, but the frame/pan block my view.

coolant-spray.jpg


My guess is that the thermostat is opening, and for some reason the pump sees increased pressure and the water sprays out from behind the pulley.

Water pumps are cheap, but the operation is time-consuming.
 
The standard failure mode, in my experience, is that the bearing goes, which causes noise and/or vibration, then the irregular shaft motion eventually takes out the seal, so it leaks around the shaft. Often you can see the pulley wobbling when the car runs. If you see that, you need a water pump for sure.

And, yeah, you have to dig for it a little, but it's not like you have to pull the engine or anything. Just be glad you don't have to do it for a modern car!
 
:iagree: Also, you might remove the belt and spin the pump. If the bearing is gone you should be able to feel or even hear it.
 
Mind you if that's where it is, it's most likely the pump
 
I also vote pump.
 
I would inspect the hose that goes from the water pump to the bottom of the radiator really well and see if it needs attention. In my experience these tend to fail at the joint where the heater return hose joins the main hose.

Without a doubt I would replace the bypass hose too, number 11, which runs between the head and the water pump. It is about three inches long. I had that one go last summer. The space between the head, pump is minimal and blocked by the radiator filler neck it is just a real bugger to change. I had to pull the radiator to do it--very easy to do with my Bugeye, not sure about your car.

Every other hose on the car had been replaced over the years but that bypass hose had not been replaced for many, many years.

Time for a six-bladed plastic fan? I don't know if one would fit.
 
I'll replace those hoses as a matter of course. They look old and troublesome.

Good time to put in an electric fan? It would take some of the strain off the bearings of whatever water pump goes in there...and maybe even keep this thing from dying in surprise traffic.
 
The 2-130 VB pump you are showing looks a little updated from what they were selling 2 years ago. It looks more refined, if that makes any difference.

I agree, replace all the hoses that is cheap and a nice piece of mind.

Mark
 
Very good writeup!
Only thing that I would recommend is to drop the radiator in and hook up the bottom radiator hose BEFORE you put any radiator bolts in.
Just makes it a little easier if you can move the radiator (but it still won't be easy!!!)
BillM
 
Back
Top