Contour Enthusiasts Group Archives Forums General Troubleshooting Burping after water pump change

Janine,
Thanks for the informative posts.
I understand what you are saying about the repeated flushing, but how effective can it be when there is no drain plug for the engine block on the 2.5 V6? If there is any sediment broken loose it would have to wind up in the radiator in order to be removed during drain.

"Cone" is the stainless steel part of the housing that pump impeller closely mates with to allow pump to operate. It has been known to come loose, generally requiring new OEM housing (c/w plastic impeller).

Don't know how similiar your '95 is to my cars. On mine, reservoir has one large hose to bottom and 2 smaller hoses above coolant level. These latter hoses allow air to "self-burb" from rad and thermostat area, regardless of speed of the pour, with reservoir cap in place.

Unless you specifically checked new thermostat, I would not discount faulty one. Has happened to me in past, although after a few weeks.

p.s. Lingering question would be % anti-freeze in system. Did you flush system after new wp installed, or simply add 50/50 (about 5 litres)?

Roger,

I hope this is not your problem, & most likely isn't, but as you may know, these engines can overheat & be seriously damaged in less that 2 minutes, partly due to the design of the temp gauge - it doesn't spike until it's almost too late. Is your coolant level holding? No steam from the exhaust pipe? (Symptoms of blown head gasket.)

The customer I mentioned had no damage, fortunately, except for the coolant temp sensor - car runs fine now after replacing it - I wouldn't rule that out, but again, unlikely.

The WP is a poor design w/a cone that easily displaces, & a plastic impellar. Many are replacing theirs before they disintegrate, as a preventative measure - 40,000 miles is about the average lifespan.

You have 3 choices:

1) Replace w/an aftermarket metal impeller pump, which I decided against, since a shattered metal impeller from a loose cone would be a worse problem, IMO, than a plastic impeller in pieces. You will still be using old housing w/old cone.

2) Replace w/aftermarket plastic impeller pump. Again, you will still be using old housing & cone, & since impeller is plastic, I would replace every 40,000 miles.

3) Replace the whole unit, only available from Ford, including cone & impeller, so that you now have a new cone & housing. You will still have a plastic impeller, though, & since apparently no one knows if the new plastic impellers hold up any better, I would still replace every 40,000 miles. Some feel this is the best way to go, since at least you will have a new housing & cone, & maybe the cone will be less likely to come loose than one that has been on for awhile. But this unit is more expensive. And, I had a customer who got 2 defective units in a row from Ford, but I have never heard of anyone else having this problem, so I'm hoping it was just a fluke.

I'm getting ready to do mine, & I think I'll go w/the plastic pump we sell at Advance, if my cone looks OK when I pull the old pump out. There is no perfect solution here - some compromise is involved w/each choice.

With regard to flushing, ideally it is best to flush the radiator, engine, & heater core separately, by disconnecting hoses & removing the thermostat. This really isn't practical unless you are replacing hoses & have the thermostat out to replace it.

I feel the easiest way to go is to use a Prestone Flush Kit.

I would first drain the system at the radiator, & then flush the radiator w/a garden hose in the expansion tank w/the radiator drain open. Then close the drain, & fill the system w/water, adding a commercial radiator flush (such as Prestone's Super Flush). Replace the cap on the tank & run the engine w/the flush per directions. Allow to cool, remove cap, & then follow the directions on the flush kit package - tap into the heater hose between the battery & WP w/the provided tee. This hose is already divided - no need to cut it -just unclamp. The kit includes a spout that fits in the neck of the expansion tank to divert the flow while flushing - you might want to put a piece of hose over it to direct the water away from the engine. Or if you don't want to use the kit, you could just separate the heater hose & force water from your garden hose into the heater hose going to the heater (firewall) - water will flow out of your expansion tank. Either way watch water pressure - keep it low - heater cores are easily damaged from high pressure. Drain water, then fill system as explained below, with 4 1/2 quarts of coolant (V6). Top w/water (preferably distilled) up to MAX line.

Sometimes it is a problem getting the 4 1/2 quarts of coolant (needed for a 50% mixture) in before reaching the MAX line, since quite a bit of water remains in the engine even after draining at the radiator. Leave the cap off of the flush tee, or leave the heater hoses (where you tapped into them) disconnected, while filling w/coolant at the tank, & watch for the water flowing out of the hose to turn green turn - you now have displaced the remaining water - put the cap back on the tee, or reconnect & clamp hoses, & top off to MAX line w/water. (IMPORTANT: Filling this way, w/the system still open, also helps to displace air in the system.) To make certain that you do have the proper 50% mixture, I would later check w/a coolant tester.

Yes, this engine is theoretically supposed to burp itself, but some folks do have problems w/this, & the Haynes manual does state to pour slowly to prevent air pockets, so, hard to say. The manual also says to squeeze hoses & remove cap after driving & cooling off, to help release trapped air.


Hope this helps, & let us know what you find out.

As I said, I'm getting ready to do my pump, thermostat, & a thorough flush in a few days, so I'll find out soon if I can get all this to go smoothly!!

Make sure your coolant level is at or just below "MAX" in the tank. Mine was running hotter than before -- up to the "M" in Normal -- after replacing the water pump.

Removing some coolant got it back to the "N" in Normal. This is where it always was before.

(My pump just went at 207,000 km).

For emissions and driveability issues, stick with a T-stat with the same temperature rating as the OEM one. A lower temperature rating one can cause problems in this regard.

OK,
thanks all. Tomorrow (or tonight) I will be changing the thermostat for starters.I had installed an aftermarket (180) and now I have a 'quality' Ford one, which is supposed to be a 180.
When I did install the new impeller (plastic), the cone looked ok, but, I was not aware of its issue of coming loose .I was amazed at how shiny and bright it was, and therefore assumed all was well in there.I don't think it had shifted.
I will report back my progress.

Hmmm...that's interesting. I'll watch that when I refill. Maybe too much coolant in the tank prevents the system from being able to burb itself??

Do you thinks it's possible, though, that trapped air was purged when you removed the cap (to remove the coolant), & that's what helped?

As I mentioned above, Haynes does suggest removing the cap (or disconnecting the upper radiator hose), after allowing the engine to completely cool, if you have an overheating problem after draining & refilling.

Here's the exact quote from the manual, under COOLANT REPLACEMENT, for anyone who would like to read their suggestions:

"NOTE: If, after draining & refilling the system, the engine overheats (but didn't previously), the problem is almost certainly due to to trapped air at some point in the system, causing an air lock and restricting the flow of coolant. Usually, the air is trapped because the system was refilled too quickly. In some cases, air locks can be released by tapping or squeezing the various hoses. If the problem persists, stop the engine and allow it to cool completely, then remove the expansion tank cap or disconnect the radiator upper hose to purged trapped air."

I'm no expert, only a lurker. I just signed up to to add the experience I had over the last two days.

But, I think that if the top hose that leads to the overflow tank is not clear of fluid, the engine sucks a percentage of the coolant directly from the overflow tank *before* it passes through the radiator.

This means the overall temperature of the fluid is higher, but not enough to be overheating the engine because most of the fluid is still passing through the radiator.

Only a theory and I would hope that someone with more knowledge could set me right. But it did solve my problem.

What I meant was the *bottom* hose. Sorry.

Temperature is OK now.This morning I got up at 0600 hrs ,redrained the rad, etc and changed the aftermarket thermostat that I had installed last week (Motorad brand) .I put in a Ford Motocraft thermostat, added new antifreeze, slowly...started up the engine until it got to operating temperature and took off down the road for a few miles.
The temp gauge needle stayed down by the 'N' where it had been before the problem started.
Thanks, all for your thoughts.
Good luck with your cooling systems.

Roger