P38 1999 thor 4.6

Hi Folks I have been trying to decide if I should rebuild the engine in my car or not bother ,I did a compression test on it today and the results were all eight cylinders were between 10 and 10.5 bar ,do you think these are acceptable figures or do I have a problem ?.

1 bar is atmospheric....not sure what the comp ratio of the THOR 4.6 is off head, but those readings would suggest around 10:1 (and at 14.7 PSI to 1 bar....thats around 147 - 155 PSI) so I'd think they ain't too shabby and aslong as they are all in the same ballpark I wouldn't worry....

Do you have a specific reason to do a rebuild?

Thanks Saint the car runs spot on does not use any oil or water and will sit in traffic until the cows come home with the temp gauge just below the middle ,I bought it 2 years ago from a member on here and it has not missed a beat since the oil light goes off with in a second or two of turning the key,BUT when warmed up and idling there is a chattering light tapping noise its fine until normal temp no loud knocking just this light clatter I am wondering if it could be the timing chain .

*could* be chain slap - but even when stretched on the Rover V8's, they are not *usually* loud enough to be heard over the engine running to any degree...maybe a little rattle.

*could* be tired hydraulic cam followers getting a little loose or their oil ways getting a tad blocked up with old oil and sludge deposits.

If she runs sweet, no overheating, smooth and powerful....I'd leave the heads well alone.

Cam followers and chain can be done with heads on....when was the oil last changed?

The oil was changed about 300 miles ago I change it about every 3 to 4000 miles as we only use the car at weekends .The wife really loves the car it is ideal for us drop the suspension get the dogs in the back plenty of room , we take them to a load of differe
nt woods press the button up goes the suspension ,we do a bit of green laning now and again press the button again suspension goes up for greenlanning ,we can get all our walking gear and the dogs in it I even have a Carannex that goes on the back so we can stay away for a couple of days .Just don't what it going tits up because I am sure I will get a right ear bashing .

Definitely tapping and not ticking?

Its really hard to be precise about the noise ,I don't think its coming from the valve train if that's what you are thinking it seems to be lower down in the engine the sump area .I have a print out of Saints write up on changing the big and main ends so I may change them and put a new cam and chain in .I have an oil filter sandwich plate in the garage which I will fit next week so I can connect a oil pressure gauge and check the oil pressure .

I bought one of those Gunson electronic stethoscopes off the Bay for £20 the other day. It is excellent for tracking down noises as long as you can access places!

MrGorsky had a tick that turned out to be the head blowing.

There's the oil pump in the front cover too, IIRC. If oil light staying on for a second or two I wonder if that might be worn or blocked up? I seem to remember several channels in that front cover that could get blocked. Is the pressure release valve in there too?

Now that is a bloody good idea Grrrrrr I will order one .Oil light goes out within a second or two of turning the key never comes back on while the engine is running.I think I will change the main and big ends later on just to be on the safe side while I have it in bits I will put a cam ,chain and sprockets in . I have put a 2 1/2 inch stainless exhaust on it and it sounds the nuts ,I live in a small Cul de sac and most the neighbours came out to listen to the car when I started it after fitting it if I go green lanning almost every one say how nice it sounds COULD IT BE ME ?.

Boys and their toys. My latest is a blood pressure monitor.

DO NOT suggest I get one of those Tom cat ,I am having enough trouble with a ticking coming from the car imagine if I found a problem with my blood pressure .

boycie said:

DO NOT suggest I get one of those Tom cat ,I am having enough trouble with a ticking coming from the car imagine if I found a problem with my blood pressure .

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No need for a blood pressure monitor when you own a P38, you know full well your blood pressure is going to be off the scale most of the time!

I thought it was just me ,we went out to the car a while back put the dogs in the back got in turned the key light's came on turned to start nothing tried a couple of times nothing" that's it the key has gone out of sync" I am flapping around got the bonnet up listening for the click Jackie says "why don't you put it in park and try again " what a plonker yes it started straight away .

Done that a few times.

What's park

The big green flat thing with swings up the road .

boycie said:

The big green flat thing with swings up the road .

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Perv.you will get locked up.

Blown exhaust gaskets can sound like a tapping oddly enough.

Thanks I will check the exhaust tomorrow .

tomcat59alan said:

Boys and their toys. My latest is a blood pressure monitor.

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Got one of those too, although my mother usually has it.