Head gasket change - now no compression on 3 of 4 cylinders
Paul
engine).
All seemed to go fine until the point of starting the engine which flatly
refused to start.
On refitting the timing belt, I'd ensured that both the crank and camshaft
were lined up with the TDC marks, and confirmed the camshaft by checking
that the rotor arm was in the position to fire on cylinder 1.
However, cranking the engine resulted in just a smooth turn over - no
"compression stutter". Continued cranking resulted in a slight stutter at
which point I got the compression tester out.
Cylinder 2 showed about 9 bar after 2-3 strokes. However, cylinders 1, 3 and
4 registered nothing.
I'm thinking that it's now officially dead, but what's bugging me is:
- What's happened to it - compression was fine before the gasket went
- Did I miss something (to do with the valves maybe?)
Cheers
Paul
Matthew Long
"> - What's happened to it - compression was fine before the gasket went
> - Did I miss something (to do with the valves maybe?)
It's not dead! Vauxhall OHC engines are known for this! Keep winding it over
and over. Might need a second battery! Sometimes the hydraulic tappets can
take ages to pump out, and before then, they spin over like you have all for
spark plugs out!
I had one once, where I nearly done the starter motor in because it got so
hot from spinning, so don't spin it continually for more than 30 seconds at
a time. When it does burst into life, it might be just on one cylinder, and
when it's able to run on it's own, it'll probably misfire for quite a while
afterwards!
Good luck, let us know how you get on!
Matthew
Adrian
like they were saying:
> It's not dead! Vauxhall OHC engines are known for this! Keep winding it
> over and over. Might need a second battery! Sometimes the hydraulic
> tappets can take ages to pump out, and before then, they spin over like
> you have all for spark plugs out!
Blimey, I know the hydraulic tappets on the Saab took forever to pump up
and quieten down after doing the HG. I'd idled it up to the fan kicking
in, and they were still loud. It was only when I took it for a run that
they shut up. I'd hate to have to do that on the starter motor...
Mrcheerful
assuming you have not done something very silly, then you may find that
after leaving it for a while it will go. Sometimes the tappets expand while
unloaded, they then take a while to recompress and in the meantime hold the
valves open, hence no compression. I changed a Rover HG the other day, on
starting it was three at first with blowing back in the inlet, after a few
minutes of running on three the other one came in and the chuffing stopped,
in that case I am certain that at least one valve was being held open.
Pete M
I built a Rover V8 lump that hadn't been run for about 20 years and
honestly thought it was fucked when if first fired up. Rattled for about
20 minutes (at 2000 rpm). When it did eventually quieten down it was the
quietest Rover V8 I've heard. Still a scary 20 mins though.
--
Pete M - OMF#9
Range Rover V8 Turbo
<space vacant>
"Professional Petrolhead"
Mrcheerful
I did that with a secondhand renault engine that went into an audi 100 IIRC,
it was promised as a great engine, but when I fired it up it rattled
awfully, I phoned up the breaker who supplied it, he said to let it run for
half an hour or so !! He was right though, after nearly half an hour it
quietened down to normal levels. I must admit I was really surprised at the
time.
Paul
I went out last night with the intention of using up the last of the battery
before charging it overnight to continue cranking today, but it burst into
life almost straight away.
Went from no compression in 3 cylinders when i left it on Sunday suddenly to
being fine last night.
It is still a bit rattley, so I'm charging the battery up anyway and will
take it for a run tonight. However, it's parked on a steep hill and was able
to do a hill start fine so can't be down on power too much.
Cheers!
Paul
"Matthew Long" <No...@m.com> wrote in message news:fsrfrl$lcq$1...@aioe.org...
Mrcheerful
Paul wrote:
> Good call!
>
> I went out last night with the intention of using up the last of the
> battery before charging it overnight to continue cranking today, but
> it burst into life almost straight away.
> Went from no compression in 3 cylinders when i left it on Sunday
> suddenly to being fine last night.
>
> It is still a bit rattley, so I'm charging the battery up anyway and
> will take it for a run tonight. However, it's parked on a steep hill
> and was able to do a hill start fine so can't be down on power too
> much.
> Cheers!
> Paul
>
frightening isn't it? you think you must have cocked up at first and start
going over everything, been there done it etc.
Mrcheerful
Paul
Not knowing what was wrong was bugging me more than the fact that the car
seemed dead, when all seemed to have gone well while I was doing it. (That
and a few hours down the drain!)
I'd kinda come to the conclusion it must be valve related, but couldn't work
out why. I didn't realise it had hydraulic valves - Must admit I didn't
really look at them too closely when I took it off.
All good experience....
"Mrcheerful" <nbk...@hotmail.com> wrote in message
news:gUoIj.142$yD2...@text.news.virginmedia.com...
adder1969
while is the italian tune-up.
Hydraulic lifters usually close up when they're off (meaning the
valves will be closed and you get noise). I'd be surprised if the cam/
head could be fitted if the lifters were so long that they kept the
valves open all the time but I guess it's possible.