Welcome to vvon

fsurfer · #1 10-05-10, 22:27

I recently went over a crest of hill and came down with a thud. Since then I sometimes have a hollow gear meshing noise and a loss of power.

The car is a 2000 Vectra 2.5 V6 92,000 but the engine have only done around 12,000 and was installed in 2005

At first I thought it may be the EGR valve as the add-ons are original, so I blanked off and the problem went away. The car has loads of power and did the school run as normal no problem. Later on I went for a short run...less than a mile, not even enought time for the engine to reach normal temp and on the return the strange hollow noise came back and loss of power.

So the EGR valve isnt the problem.

I recently fitted Bosch Super 4's so I though lets return to basics, removed the manifolds, then the plugs - all are a normal colour, replaced with the std NGK's and removed the EGR blank. So everything is back to the way it was, tried a few trips seems ok.

Has anyone had similar symptoms on their Veccy?

I'm wondering could it be timing tensioner as I had a strange noise during the bitter winter we had from the timing belt area.

matt-m · #2 10-05-10, 22:33

tech 2 may be the ansewer its poss a crank sensor ?

fsurfer · #3 10-05-10, 22:39

It sounds like gears trying to mesh and luckily enough I have just bought a new sensor as the limp-home light came on but went off again so I haven't fitted.

Not sure if this is relevant, 3 week back - coil pack went, so that's new and don't laugh, but since the winter applying the power when doing sharp right turns at the lights, makes the engine grunt loads of noise but very little drive

Leeky · #4 10-05-10, 22:43

Did your cat/exhaust downpipes sustain any damage during the impact with the ground?

Its not a crank sensor, as that either works, or doesnt and neither does your engine.

I'm putting myself on a limb here, but I'd be looking at your cat. Its possible you've damaged (into pieces) the internals, and its blocking the exhaust gas flow, reducing your power. That will create a meshing, perhaps rattling and what can only be described as shaking salt in a tin type of sound.

If the cat is blocking you WILL lose power. Safest bet, get your downpipes off, and see if the internals fall all over the floor. If you hit it hard enough, you might even hear the internals if they are in bits, but I'd always recommend you remove it first for obvious reasons.

I'm fairly confident it wont be engine electrics on this occasion.

Best way to test the clutch is: travel to, and hold at 40mph, stick car in 5th gear and floor it. If the engine revs increase (e.g. the car revs up) but the speed doesnt move then your clutch is slipping. Its possible you've damaged the clutch plate, or the fork bearing, but you'd get it continiously if it was the case.

matt-m · #5 10-05-10, 22:43

thats ure clutch then bud its called clutch slip

fsurfer · #6 10-05-10, 22:52

I'm thinking book it in for an estimate with my local reliable garage as the dealers are silly money. I'll try the clutch tomorrow.

fsurfer · #7 10-05-10, 23:01

Just thinking, if it was the cat surely it would be all the time and I haven't noticed any increase in revs when pulling off in 3rd.

Have notice the occassional vibration from the heat plate, but thats normal.

Exhaust is stainless from the Cat back.

Leeky · #8 10-05-10, 23:03

I'd check the clutch as above, then book it in your local place of choice. If the clutch is slipping, you'll need a full clutch kit, and a slave cylinder. Do not, under any circumstances ever replace a clutch without also doing the slave cylinder as it will fail. If it will pull away in 3rd then its clearly not going to be slipping. Its not very wise doing that though.

You might be lucky though, it could still be the exhaust.

The downpipes are weak, and only made from mild steel. The cat might only be doing it once it gets warm. Does it pop and rattle when cold and first started for the first few secs?

fsurfer · #9 10-05-10, 23:14

As the lump has a lot of torque I forget to change down and think wow I'm still in third.

Oh I forgot I have recently changed the top engine damper as that had gone.

Yes it does pop a bit in morning as I have twin exhausts cat-back, but would the cat make a gear meshing, nuts in a can type noise all of a sudden and then go away?

Leeky · #10 10-05-10, 23:28

Yes, the flexy pipe can make a similar sound. Its hard to describe unless you can also hear it in person. It could well be the gearbox, but I find it unlikely (but it doesnt mean I'm right, I cant see the car remember).

Can you roughly locate the location of the sound? Is it underneath you, or towards the passenger or drivers side at the front?

The popping will likely be the secondary air pump, which is the round cylindrical plastic component to the right of the battery, tucked into the passenger wing. The seals are known to degrade over time, causing it to leak. If your cat is blocking, then you'll notice the exhaust gases venting through this component due to back pressures not being able to escape through its normal route.

I'd get the flexy and cat checked over mate, or do it yourself. Its probably frayed and splitting already. I went through loads of downpipes when I had a 3.0 V6 lowered 50mm. lol.