Water pump Woes... I think?!?! (Read 134 times)

[unclesilvia]

Hi all
Wonder if you can help?

Ive been driving my B310 coupe for the last year with no issues at all with the cooling, but the last few weeks its been getting a little warm when on a fast road or motorway. It even over-heated once.

I decided to give the coolent system a flush through and replace the fluid with new. I also got a bit of gunk out of the system.

However, this hasnt seemed to cure it!!
it still creeps up the gauge to over 3/4 on a normal fast run and even higher up big hills. If I turn on the heaters it does reduce the temperature slightly.

Ive checked there is no evidence of head gasket issues.

I did run the engine at fast idle with the rad cap off and the water didnt seem to be moving much and certainly didnt bubble over when hot.

Im thinking the water pump isnt pumping efficiently??

IF im correct here can someone point me in the direction of a replacement for reasonable cash? I believe there is several different versions???

Cheers, Scott

[Al Ramone]

You really shouldn't keep running it when you know it's got too hot.

i'd say it could well be a blocked rad. have you felt the rad all over once engines up to temperature to see if you've got cold spot?

also bet the head gasket has blown. pretty common due to age of them.

i've had a few blow, and the fact you cooked it as well means it's even more likely.

you'll prob find number 4 cylinder is blown into the waterway.

cold starting you would notice a slight missfire till the water clears.
also might hear the bubbles going throu the heater.

head gasket is very easy job on these though

[barnzey]

one of the draw backs of early alluminium heads, great for coolin but bad for warping. Mine had exact symptoms before i swapped it an i knew that was head gasket problem

[unclesilvia]

When i say it over heated it only just touched the max line then I stopped and let it cool. Seems to run fine at all times and doesnt loose water, smoke or steam. No oil or water is mixing either.

It sits at about 3/4 up the gauge on the motorway and only went higher on a really steep hill once.

It may be a blocked rad, ill check for a cold spot. Could it still be a pump issue?

Problem is im away on holiday from wed right up to next wed, leaving me only 2 days when i get back before RRG12!!! I really hope i can sort this or I may be buggered!!!

Its also my only mode of transport and my daily car!

[Al Ramone]

2 days should be plenty of time to get the head off if you know where you can get it skimmed?

[unclesilvia]

Yea but dunno if needs booking in as they often busy! I may get a mate to look at it while I'm away!!

[unclesilvia]

Well... Hopefully I've cured this issue for £8

Last thing to check was the thermostat! I changed it for a new 82C one as the old one seemed to be a bit gunked up (and the origional one from new it seems lol).

After fitted I took it for a run at 70+ up the motorway for 20 mins... And then proceeded to get stuck in near stationary traffic for another 20, and it never went over half way

Result... Hopefully

[Al Ramone]

well thats very good news. keep us posted

[RatDat]

Just for the record, I've had a lot of A series and the only time I've had them blow a head gasket is on engines that have been stood unused for a very long time. I have NEVER known one to warp a head, even when heavily cooked. That's not to say it can't happen, but it must be pretty uncommon. They are amazingly durable little engines.

One piece of equipment that is very useful to have is a laser/IR thermometer. You can just point it at bits, squeeze the trigger and take instant temp readings. You can use it to determine if you have coolant flow, if a rad is blocked and if a stat is working. You can even use it to tell which cylinder isn't firing when you have an engine running on three. Very useful.

[datman]

Never known a waterpump to not pump properly, that would be the last thing I would suspect. Clogged rads however, very common.

[RatDat]

Definately not on an A series. Seen it happen on other cars, especially modern ones like my Alfa, which are known for water pump impeller failure (it's plastic from the factory!). Datsuns on the other hand have robust, all metal pumps.

The only A series I have had with serious overheating was an A14 which had been layed up for years. The water jacket in the block was half solid with rusty crud and scale. A soak with phosphoric acid would have probably fixed it, which is also a cure for clogged rads. Chemodex Rust and Scale remover is top notch for this sort of thing

[Al Ramone]

most the A series engine's i've had (possibly all) have been standing a long time....

i've also had a couple of blocked rads, where they are full of what looks like alloy sediment. possibly from lack of antifreeze/corrosion inhibitor?

[gainsb1]

Having read this thread, the old adage seems to still hold here....
Start with the cheapest/easiest thing to replace/repair and work upwards. So, thermostat then radiator (flush first; then replace with a secondhand one from Will, perhaps) or pump.
For this thread, like Will, I would have suspected the rad being gunged up, so a flush out. Then on to the thermostat.

Leigh