www.RX7fb.com

Hi All,

I'm trying to search and read up as much as possible, but since my initial introduction post you lot seem friendly and knowledgeable so I thought I'd get a thread running.

Picked up the car up a week ago and drove it home for over 3 hours in one go, ran beautifully.

Set off for an hours trip today and about 40/45mins in the engine started losing all power so I had to pull over and stop. Engine was overheating, steam escaping from the top right of the rad where the main hose goes in. The fan fuse had gone so I checked the wiring to the controller, no snags or shorts all seemed fine. replaced the 30A fuse with the power windows one but it blew straight away.

I left it to cool right down, topped up the water then fired it back up and manage to get the last miles to my destination driving normally.

After a good 30mins left to cool, I popped to a garage to grab some 30A fuses, this time it didn't short and fired right up.

set off home again watching the temp gauge, which didn't go above it's usual quarter/third up spot, but the engine died again about 20mins in. it would fire up and sometimes rev happily, other times it feels like it's fuel starved and will just bog, splutter and die.

not seen any white smoke out the back and I turned it over with the rad cap off and it didn't look all turbulent which I read can be a sign of the engine seals being shot.

I also noticed a fair bit of white sludge coming out of the oil breather hose next to the oil filler cap :/

So I'm gonna chat with the previous owner tomorrow, see if he has any ideas, anyone got any thoughts?

Thanks in advance.

engine pics to help:

Hi,


Theres clearly a wiring issue with the fan, if your not sure where to start looking then i would get an auto electrician to sort that and see if the fan working stops the overheating, it may be that simple.

Worst case the boost is pressuring the coolant pipes and causing the burst and subsequent overheat, which is an engine rebuild job, you can check if the top hose is going hard when revving the engine, theres possibly better ways to test this though. But obviously if it does go hard then thats your issue...

I would still reccomend professional diagnosis though.

Rich

I can see water spurting out of the top hose that's for sure. The fan shouldn't come on while cruising as airflow through the radiator should keep it cool. Is the radiator blocked? Is the fan controller probe in the top hose causing pressure issues? My car was overheating from a small leak from the coolant level sensor at the top of the radiator

Thats what i thought; the fan shouldn't be required at normal driving speeds. My plan is to drain the coolant system and give it a good flush through.

After its first long journey in a while when bringing it home, I noticed the two main large rad pipes had collapsed slightly, after taking of the rad cap the suction pressure released and they returned to normal. So something isn't quite right.

Going to stick a new fuel filter in as well, the car hasn't been used much at over the last 10/15 years so there could be some crap in the tank.

Ah well, this is how you learn how they work

Thanks for the replies, will keep you updated. Already got some nice bits to go the car so hopefully my next post will be about that!

I would check/change your radiator cap, ensure it is the reclaim type (13lbs I think) & thermostat as it could be sticking & not operating through the expansion tank properly, they can be purchased from a factor. Give rhe cooling system a thorough clean with a good Rad Flush product as it is common for sludge to build up.
You must use de-mineralised water as the different materials in the engine will cause corrosion if using tap/rain water.
regards Pete

Is this a series 3? I wonder if Rexi/Adam(?) still has any silicone radiator hoses left? If you're replacing them anyway

2 X Screenwasher jets = series 3

Should be no steam at that point under any circumstances.
If the hoses are sound, then I would guess the radiator header soldering has failed? Rad rebuild with new core will solve that.
But loss of power as well??

Yeah I think I have two problems going here:

Im going to replace the rad with a new one, any recommendations? So far found the kyorad and silla from the states. Also going to swap the hoses and rad cap and obviously flush the whole system.

The power loss I think might be crud in the fuel line or tank. So new filters will be going on and I'll see what the fuel coming out looks like.

I take it no one actually makes a replacement tank for the fb?

Hobbawobba wrote:Is this a series 3? I wonder if Rexi/Adam(?) still has any silicone radiator hoses left? If you're replacing them anyway

I've only found one set of hoses from the states, if someone has some in the uk for sale that'd be great!

Have you tried Mazda as I got a set from them a few years back ?

Dibs