Hi,

I know you should always use deionised water (I think its battery water, or maybe thats distilled water I dont remember) in the coolant system, however, I was in a situation where only tap water was available.

Anyway, after that I didn't use the RX7 FD for 6 years....what I want to know is would there been alot of corrosion generated by leaving the tap water in the system even though I didn't actually use the car?

thanks for any help.

 

Absolutely.

 

6yrs of just sitting...im pretty sure its going to be corroded a bit along with many other things

 

distilled water is the best to use but i've always used regular tap water with no ill effects.

 

You've had it sit static for 6 years in a motor and had no problems? This is what he's asking.

I foresee giant chunks of iron blowing through the coolant passages, clogging up stuff and maybe even taking out the water pump if the engine is actually just started w/o a good back flush.

 

i just think the whole ordeal is not going to be good. 6 years just sittin is a long time. i mean you have to realize this isnt a 2004 thats been sitting for 6 years.....

 

Hmmm, ok so it's probably not a good thing. Remedies anybody??
Backflush...what's that, do you mean flush the system with some Radflush stuff from Halfords? Will that do the job ok?
I am just about to change the oil, do you think it's necessary to renew the oil filter? The car had this done in the shop a few hundred miles before I stopped using the FD but it was a looong time ago...
I am also renewing the HT leads n plugs aswell, it's been a bit reluctant to kick into life.

 

I would change the oil, oil filter, flush the cooling system real real real good and possibily flush some sort of cleaning solution threw the cooling system. change the plugs, change the FUEL AND FILTER, if theres any rotted rubber lines change them at least the ones that have pressure. Can i ask y would you not drive a perfectly good FD for 6 years?

 

change everything dude, take no risks with something thats been sitting for 6 years. mine had been sitting for 3 years and i drained everything and replaced all the hoses

 

Hi guys thanks for the input, I will get onto it...

well shortly before I stopped using the FD I discovered that it probably needed a rebuild due to an O ring failure (check my other posts). I didn't have the money to do this or run the car anymore, insurance is expensive, petrol expensive etc etc etc.
I bought a motorbike to get around London on, as I only spent most of my time in traffic jams when I was driving the FD anyway!!

 

oh no, it's driven every day. i just didn't read all of it.

but as with any vehicle that's sat for that long, u'll need to flush the cooling system. also wouldn't hurt to have the radiator cleaned too just to eliminate it as a problem area when u do start driving it again.

 

no man, I haven't driven it for 6 years.

 

haha, bought a motor bike. thats great! i never been to london its kinda far away lol but it does seem like everything moves slow there and everyone has them motor bikes. what are u planning to do with the FD sell it?

 

Any car that has been sitting for 6 years is going to have a lot of issues. See the link below for an idea. While it is geared towards 2nd gens, almost all of it applies to all generations of RX-7.

http://www.aaroncake.net/rx-7/unstore.htm

Tap water should be OK due to the additives standard in all coolants. But still not recommended. That said, I almost always just use tap water.

 

HaHa, moves slow......more like the opposite, it's similar to your New York. The only people that ride motorcycles here are either couriers or city workers commuting due to the morning congestion or the full up trains/tubes. It's not like Vietnam where absolutely everyone rides bikes..nooo lol

 

Thanks for the info Mr Cake, I will check it out.

 

SOFT tap water can actually be better, assuming you are using a 50/50 mixture with a good quality antifreeze like prestone.

Mainly because the inhibitor packages in modern coolants are designed to use tap water. Softer is better because it removes the minerals while keeping it stable.

People use distilled water, which is also fine. But actually can use up the inhibitors in the glycol faster, because it is not as chemically inert as soft water.

If you are using just water with an additive like water wetter. Then it is a whole different discussion.

 

Haha, this is starting to sound more lie a Chemistry lesson....where would I find soft water??

And Mr Cake, thanks for the link, very informative. With regards to putting some oil down the spark plug holes prior to starting it, I've read that people use 2 stroke or 2 cycle oil, but would normal 10w 40 do?

 

Good point...that's what I use...I've got a "whole house" water purification set up and I made sure that a nozzle output was installed in the garage. I have to fill the purifier up with rock salt every three months and change filters yearly as upkeep but it's nice having that filtered water with the hard minerals taken out as a "good water" source for my cars and washing.

We never see anything below zero as far as temps go in the Metroplex area (DFW), so I personally only go with 30 glycol/70 water for the RX-7's...since the vert 'Bird is a V8 and different altogether in cooling characteristics, it runs Water Wetter, 15% glycol, 85% water. Water is more efficient than glycol in transferring heat and the traditional Pontiac big cube V8 gets freakin' hot even with a 4 core monster radiator and no AC in Texas. One of these days, I'll convert it to the Evan's stuff.

 

To be honest i ran a 30/70 for a while too. The only downside is you have less corrosion inhibitors. Thus, you should change it more often. Water is more efficient than glycol yes but it is also more efficient at causing corrosion

If i were to run anything less than 50/50 again i would somehow use deionized water. (not readily available).

I am converting my RX7 to evans as well. There are soooo many up sides for rotary engines. Not the least of which is being able to run a 1-3 psi cap.


From someone who has a water softener in their house. I get mine right out of my laundry sink...

 

Or from your unfiltered taps if you are lucky enough to live at the BEST end of the UK

 

haha, the best end whats that, I'm half Scottish!! anyway we have very hard water down here. But I can get hold of deionised water pretty easily so I will get some of that.

 

Any type of oil will do the job. You just need to get something in there to avoid a dry start. There will be surface rust on the irons, rotors and seals, which you want to avoid grinding off.

 

The damage to the cooling passages will not be a big deal compared to the damage caused if there was coolant laying in the combustion chamber all this time.

In any case, since the engine needs a rebuild all of that will get sorted out. Change all coolant hoses that are questionable and use distilled water and fresh antifreeze when the engine goes back in.

Dave

 

Thanks for all of the info guys I appreciate it, I'm going to do the test to see if there is coolant leaking into the combustion chambers soon, I will keep my fingers crossed...