Dumb Question Thread!

how long does it take to warm up ? they dont read at all when cold but they have heaters built into them to warm them up faster . hope your not just starting the car and saying the sensor is fked because it doesnt read for the first 5 seconds . or maybe the heater circuit for it is shagged and it takes ages to warm up from exhaust only ?

Should a car still roll backwards if it's in 1st gear? I've also got no front drivers cv joint

I was cleaning the brakes yesterday. I notice that with the car in park the front wheel didn't rotate , but the rear wheel did. Is this supposed to happen? I thought with 4wd that it would not. Or is this to do with the centre diff? (this was with only one wheel off the ground)

O2 sensor without element takes a while to heat up. I'd suggest that the heater element is poked but the sensor is still fine.

 tydon said:

Should a car still roll backwards if it's in 1st gear? I've also got no front drivers cv joint

Yeah, but it means the engine is rotating backwards

(I am guessing you mean with the engine off?)

If it's with the engine running for what it's worth no CV is like a broken axle, which is like one wheel in the air and if you've got old / crap diffs it can and will just one wheel (even a 4wd) given the chance. Or as you've found it'll just be like a slipping clutch as the diff sorta feeds some power but mostly not

 SpeedySub said:

I was cleaning the brakes yesterday. I notice that with the car in park the front wheel didn't rotate , but the rear wheel did. Is this supposed to happen? I thought with 4wd that it would not. Or is this to do with the centre diff? (this was with only one wheel off the ground)

I thought the centre diff in these is not a permanent one, just a clutch pack activated sort of thing (like FWD until told otherwise)

Remember the back wheel still has an open rear diff, then the centre diff to pass through before it hits the gearbox. The front wheels are locked in "Park" directly whereas the rears have a pair of links to pass through

Hence you can do mad handbrakeys without too much fear of breaking things

 Andy_Mac said:

Is it the front or rear or both O2 sensors that the ecu uses for its afr reading?

I've got a sneaking suspicion something is wrong with one of mine. With romraider it'll sit at 14.7 regardless of behaviour and then suddenly starts reading. Haven't managed to narrow it down to whether it's just not reading when cold or if just random.

If it's not warmed up will it just sit stagnant at 14.7 or does this sound more like an electrical gremlin playing tricks on me?

How long are we talking

This is why the car has a "cold start" map and why short trips use more gas than long, 02 sensors do take time to get up to temperature even with heating elements functional.

Front one is what it reads from, the rear one is what it uses to make sure the cat is functioning and not as important

 Marky said:

Yeah, but it means the engine is rotating backwards

(I am guessing you mean with the engine off?)

If it's with the engine running for what it's worth no CV is like a broken axle, which is like one wheel in the air and if you've got old / crap diffs it can and will just one wheel (even a 4wd) given the chance. Or as you've found it'll just be like a slipping clutch as the diff sorta feeds some power but mostly not

yup sorted now replaced cv with a new one and car works fine again was scared i mite of broke the gbox lol

 Marky said:

I thought the centre diff in these is not a permanent one, just a clutch pack activated sort of thing (like FWD until told otherwise)

Remember the back wheel still has an open rear diff, then the centre diff to pass through before it hits the gearbox. The front wheels are locked in "Park" directly whereas the rears have a pair of links to pass through

Hence you can do mad handbrakeys without too much fear of breaking things

Sweet thanks for that. This is the first 4WD that I have had so was a little unsure of how it workedI had a feeling it was supposed to do that but best to check. Handbrakeys on the way home from work for me!!!

 SpeedySub said:

Sweet thanks for that. This is the first 4WD that I have had so was a little unsure of how it workedI had a feeling it was supposed to do that but best to check. Handbrakeys on the way home from work for me!!!

For what it's worth there's a few different kinds of 4wd systems too - some are very tricky and some are very simple, all behave a bit different.

 tydon said:

What's the best way to remove a stuffed turbo stud

If there's enough thread to get two nuts on there, put them on and tighten them against each other. Spanner on the bottom one should then undo the stud.

Next option is weld a nut onto it.

Disaster option is cut it off with a grinder and drill the last bit out. If you're super lucky the heat from grinding breaks the seal and it can be removed by cutting a slot and unscrewing with a flat head screwdriver. If not, kiss goodbye to lots of drill bits unless you can get it into a drill press.

If the front/centre diff on my car is starting to go, is it going to be cheaper to source a second hand gearbox replacement, or just have it fixed?

Would a shagged Radiator/header tank cap cause the overflow bottle to... "overflow", and the header tank to be not full when cold in the morning? What Bar cap should be used (someone chucked a Syms sticker over mine), any ideas if not the radiator cap? Temperature is always normal (below mid).

1998 BD5 rev c

Anybody got pics of a GDB seats in a GC8? Front and back if possible? I want to see how fitment looks, considering this for my own car.

car noobie here

um just a quick question guys any help would be great!

so ive deduced that my car keeps reverting back to limp because of the afm. i unplugged it while the car was on and it made no difference.

Ive cleaned it numerous times and it works for a day or so before going back to limp.

i was wondering is it worth getting another afm.

i heard that you can replace it with a map sensor?

any tips? T_T money is everything lol

Replace with a genuine afm should be 176plus gst rrp or 116ish trade. For what youre doing the map sensor business isnt going to work.

Whats the car? For some reason im guessing its a v5/6 style afm.

 evowrx said:

Replace with a genuine afm should be 176plus gst rrp or 116ish trade. For what youre doing the map sensor business isnt going to work.

Whats the car? For some reason im guessing its a v5/6 style afm.

i has le version 8 2003

any ideas where i can get one from?

all my sources have been telling me they go for like 500+! all lies!

Talk to boon pretty sure he has a good secondhand one cheap. What i said doesnt apply. If you can wait buy one thro partsouq takes 7 daysish.