At my wits' end with this bloody ZX - intake boost results

Willy · Post by **Willy** » Sun Feb 05, 2012 3:08 pm

Surely, if it was say a brake sticking on causing your fuel consumption to be halved, you'd noticed the car being either sluggish, or that you are having to press down your right foot harder?

Surely if a brake is having such an adverse affect on economy you'd notice it through drag in coasting, or even a burning smell perhaps. Likewise any excess drag in the engine or new pumping losses would make the car sluggish, as opposed to a normal driving feel but with poor mileage.

Why not try leaving the car to idle in your drive for ten minutes or something with a white sheet underneath? Could help identify if you have a fuel leak, perhaps. Sorry if you've tried any of these already...

Oscar · Post by **Oscar** » Mon Feb 06, 2012 2:46 pm

Actually the white sheet idea is a good one. I'm sure SWMBO has just bought some new ones.

As far as your other questions go, they are good ones. To be honest I've never driven this car when it's been working as it should, so I don't know how it should feel and whether there's a drag. I might take it around the block and test those points you raise. When the front caliper was binding it was the fuel gauge dropping in front of me that alerted me. That and the red-hot wheel nuts when I got out to check them. I don't recall that I noticed a huge drop in performance though.

MULLEY · Post by **MULLEY** » Tue Feb 07, 2012 12:31 am

I'd check all of your wheels, just in case some more calipers have seized over time.

Oilyspanner · Post by **Oilyspanner** » Tue Feb 07, 2012 10:38 am

Sticky brakes are very difficult to feel from the drivers seat, theres no substitute for getting the jack out, does your ZX have discs or drums at the rear ?

Dollywobbler · Post by **Dollywobbler** » Tue Feb 07, 2012 11:30 am

If the brakes are binding sufficiently to affect mpg to that degree, they'd be glowing after a run and smelling like you wouldn't believe. Would probably get to the stage that you'd boil the brake fluid and then the lack of brakes would tell you there's an issue. You're right about not feeling it at the wheel though. I had a Saab 9000 that would sometimes suffer a seized rear caliper (handbrake mechanism I think). A really short 30mph journey would generate a daft amount of heat - ie you can't touch the wheel let alone the nuts. Yet there was very little sensation behind the steering wheel.

Oscar · Post by **Oscar** » Thu Feb 09, 2012 11:38 am

The car has drums at the rear.

When the front caliper was siezed on, there was no smell, and no fade in brake performance to show boiling fluid (although thankfully I didn't have to put it to a sharp test). We'd done about 15 m-way miles and the fuel gauge was falling in front of my eyes. The wheel nuts were hot, which is why I realised what was happening, but they weren't glowing.

Last week I did 3 miles to the supermarket and back and the fuel gauge was dropping again. Jacked the car up and tested one side - one back wheel is not spinning freely. It'll move if I move it, but doesn't spin. However I knackered the jack somehow and can't get the other side up, so will have to borrow a jack now to test.

Oilyspanner · Post by **Oilyspanner** » Thu Feb 09, 2012 12:28 pm

I have had sticky brakes that only showed up on the MOT brake rollers, Typically BX fronts with damaged handbrake cables, a lot of the handbrake cable on the ZX runs exposed and could well cause sticking, a strip clean and lube of the brakes and either lubricate or replace the cables ought to cure the sticking. Still not a rotodiesel fan though

Oscar · Post by **Oscar** » Sat Feb 18, 2012 8:52 pm

Right, got the car up on the ramps today. Offside rear brake seized on when the handbrake was applied. I got the drum off, took the lip off the back edge, adjusted the brake caliper setting, lubed up the bits of the handbrake cable I could reach and gave all the pivots a bit lube. It seems to have done the trick.

Dolly, there was no external sign that the brake was seized on - no smoke, fire, glowing red-hot drums, smell, or other sign. The wheel nuts weren't even particularly hot after a run.

Hopefully this will be the last intervention needed, and we can get back to some normal driving.

Oilyspanner · Post by **Oilyspanner** » Sat Feb 18, 2012 9:09 pm

Well done Oscar, now check the fuel return line with the motor running and you will have earned a rest

BX Meteor · Post by **BX Meteor** » Sat Feb 18, 2012 9:27 pm

Rear calipers on the Honda Accord are shit, often get a pad binding on one of the discs.

When I get out of the car, I can sometimes smell "hot rubber", but nothing is too hot to touch. Jack up the car to find which rear wheel is hard to rotate, take the wheel off, and hey presto its a pad that is stuck (again). Take the pads out (rear calipers are easier to work on than BX), spray copper spray onto it all, put pads back, and wait for the same smell again in a few months.

[before the 3 year warranty ran out, the dealer said the rear discs needed replacing, I got new discs on warranty and kept an eye on the discs myself, and that's how I associated the smell with pad binding. I think this is a known fault with Accord VII]

Oscar · Post by **Oscar** » Sat Feb 18, 2012 9:39 pm

Oilyspanner wrote:Well done Oscar, now check the fuel return line with the motor running and you will have earned a rest

Why? What am I checking it for?

MULLEY · Post by **MULLEY** » Sun Feb 19, 2012 12:14 am

A leak? which may explain the poor fuel consumption you've been getting.

Oscar · Post by **Oscar** » Sun Feb 19, 2012 8:52 pm

MULLEY wrote:A leak? which may explain the poor fuel consumption you've been getting.

Oh, I see. *facepalm*. Thanks : )

O

MULLEY · Post by **MULLEY** » Sun Feb 19, 2012 11:10 pm

No worries

I guess with all the things you've tried its easy to forget what you've already tried & what you haven't. Hopefully you'll get to the bottom of it, i'll be very interested to know what the actual problem was/is?