The Truth about this 50K rebuild claim. It is the Rebuilders looking for more ££\'s??

[Col]

I bought my car and within 3 months of ownership had to rebuild, the water seal broke at 48000 miles, the car is 12 years old though, hope this engine lasts another 12 years.

Does anyone know that once the engine has been rebuilt, it becomes weaker or should it be as strong as it was brand new???

[boltoa]

When the water seals went on my engine, I was pretty sure it was a fan problem - even if I left the car to cool after a long run, the fans stopped as soon as I stopped the engine - on most cars I\'ve owned, even with the engine off, the fans would run after the engine stopped if the car was hot. I did some web searching on this issue and noted that a recall in the States changed the fan control significantly - including fixing the issue above, but couldn\'t find any reference to this issue outside of US websites. I wonder if this has a bearing on this discussion. Any UK owners here noticed whether their fans stay on after the ignition is turned off, whether it is a UK car or a Jap import?

Andrew

[iaint]

Originally posted by boltoa
Any UK owners here noticed whether their fans stay on after the ignition is turned off, whether it is a UK car or a Jap import?

Andrew

Mine\'s an import and the fans do go off immediately after switch-off.

[Spotlamp]

Mine\'s a jap import and the fans go off straight away.  Think I\'ve seen about 104 on the PFC after a spirited drive followed by a brief break whilst I have a quick spin around Tescos (goes back down into the 80\'s immediately the engine\'s running).

Thinking about the fan thing, unless I\'m mistaken, there\'s pretty much no point in the fans coming on after the engine\'s been switched off.  If the engine ain\'t turning then the water pump isn\'t pumping, the only thing it would do is cool the radiator!

I\'ve seen some electric pump modifications which do keep the water circulating after the engine is switched off.  The seems like a very sensible mod, but I\'m not sure how expensive it all is.

HTH
H

[Durn]

Originally posted by Spotlamp

Thinking about the fan thing, unless I\'m mistaken, there\'s pretty much no point in the fans coming on after the engine\'s been switched off.  If the engine ain\'t turning then the water pump isn\'t pumping, the only thing it would do is cool the radiator!

I\'ve seen some electric pump modifications which do keep the water circulating after the engine is switched off.  The seems like a very sensible mod, but I\'m not sure how expensive it all is.

HTH
H

the coolant will thermo-syphon to an extent but yes, advantages are limited without an aux pump. Can\'t but help components generally with underbonnet heat soak though.

[Durn]

...actually I\'ll set myself a task for the summer to log tco after key off with and without fans operating. This obviously won\'t provide metal temp but should give a rough idea...

[Ricco_04]

My fans turn off when the engine is off but will come on again if you leave the ignition on (ie : lights still on on dash board)

The fans will only come on if the sensor tells them to.  When I come home and turn off the car and put the ignition on to get the fans running they wont always come on.  If you leave it for a few mins then they will come on because of the heat soak triggering the sensor.... but like you say, without an aux pump then it only has a minium effect.

[mattmaclennan]

I have bought idetical drums of antifreeze in blue and green, even the batch numbers were the same. Same with all things; "you get what you pay for". Next, there will be some clever bugger importing engine oil, petrol and antifreeze from Japan, as though it will actually make a difference.:rolleyes: Engines blow because they are not looked after/ built badly/ made with poor quality componets. Mazda Rotarty engines are hand built... surely that\'s enough of a variable for there to be no conclusive evidence as to why 2 engines blow at different millage for different reasons?

[Carl]

It is interesteing to note that Matts comments about poor quality components is true,I have had an engine fail through a poor made rotor housing and Mazda stumped up for the cost of the parts in the rebuild.

Also of note is that on the newer 2 piece apex seals for the FD RX7 there have been some that have been made over size and have caused problems,this has been noted in Australia, and the said seals were sent back,so quality control can be a problem.

As for the Antifreeze colour,i am talking about cars from Japan coming in with a green coloured antifreeze that are doing better mileages and if they do break due to an apex seals failure it is possible to see that the side housings are in pretty good condition.Also where a water seal fails I have noted that the side housings using green antifreeze fair much better than the ones with blue in.What make of green or blue is being used I don\'t know.But I know whatever it is it works.
I use the Halfords 5 year stuff which is pretty good.
Regards
Carl:)

[g11ary]

I watched the Bruce engine removal vid last night, and yes the american said he does not know of many RX7\'s that have done more than 100k. You must have an exception.

[Brett]

Moving back to the subject of the antifreeze, if this uk blue stuff is so bad/corrosive, why does it not eat away the housings in the 2nd gens I\'ve seen?  I\'ve got a pair of housings sitting on my bench now that did 155,000miles over a 14year period and the water ways are fine....  Is it that the water ways have thinner sectioned walls on the 13B-REW, hence are more susceptible to heat soak/expansion which causes fatigue, then lets this coolant impregnate the surface causing a quick break down of the alluminium?

 Have any of you guys rebuilt a 2nd/1st gen engine with water seal failure/breakdown?

[boltoa]

With the fan thing, you can keep the fans running with the engine off and ignition switch on as long as the air con is also switched on.

And yes, I understand your point about the water not circulating, but the convections currents caused by heat differential would probably be fairly significant, and blowing air over everything has got to help.

Any US owners reading this who knows anything about this fan control recall? US owners who notice whether their fans come on with the engine off?

Andrew

[t2rew]

Originally posted by col collier

Does anyone know that once the engine has been rebuilt, it becomes weaker or should it be as strong as it was brand new???

my first gen 2  had an engine built at 60 sumit thousand. i bought it with that new engine and it lost a corner of the apex seal at 37000

the other car had an engine at 80000 and is still going stong at 131000, thats 51000

both cars had good maintanance and were thrashed cenceless
i cant imagine the engines being rebuilt in the same way that they were assembled at the factory so, no