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Gary UK

How easy are they to replace?

Can you leave the engine in the car and do it via the sump??

Admin · Posted: Sun Jul 13, 2003 10:00 pm Post subject:

Hi

I am wondering the same thing. My P4 has developed a funny tapping noise. Current best guess is that it is either the big ends or the little ends. Toying with the idea of just lobbing in some new big end shells to see if that fixes the problem first before going any further.

All the best

Keith

Admin · Posted: Mon Jul 14, 2003 12:19 pm Post subject:

Hi

Matter of interest, before I start hunting for parts, how much are a set of big end shells? And are they sized (various clearances), or are they just done as one size fits all?

All the best

Keith

Gary UK · Posted: Mon Jul 14, 2003 1:10 pm Post subject:

Are the crankshaft bearings shells as well??

I have no idea about cost of parts and will be trying AlfaShop for the bit's will post the prices.

Would you recomend replacing all big or small end shells if one of them is shot, for that matter would you replace them if your in the bottom of the engine anyway (the car has 50k).

It has been sat for a long while and after removing the rocker box cover there is rust marks on the cams where they have been left contacting the tappets would you recomend rubbing these marks off with fine abrasive or just let them come off when the engine is being run in??

Admin · Posted: Mon Jul 14, 2003 4:18 pm Post subject:

Hi

I want to avoid dropping the engine, and if I have to will probably buy a 2nd hand engine to go straight in. Cannot see how I could do the little end bearings without stripping most of the engine

I would be temped to leave the rust there. It should come off fairly easily, and will be iron so will stick to the magnetic sump plug. Any abrasive you use to remove it is likely to not stick to the sump plug and will do more damage. Just give it several oil changes over the first few weeks of use

All the best

Keith

lesthegringo · Alfasud Joined: 23 Jul 2003 Posts: 97

Yes, you can replace the big end shells in situ, by dropping the sump. Not particulary difficult if you get the car nice and high. However..... why are you having to change them? If they are very worn, chances are that the crankpins will also be worn, so you may not get too much life out of them.

I did it because one of the shell halves broke in two, luckily for me not disintegrating further and screwing up the crank.

If it is just something to get you by, no problems, but if you plan on ,ore power or lengthy use, don't bother

Les

Gary UK · Posted: Wed Jul 23, 2003 2:27 pm Post subject:

A bearing has let go in the bottom of the engine (big end or crankshaft) and I need to know if you can change the crankshaft bearings with the engine in place (via the sump)

lesthegringo · Alfasud Joined: 23 Jul 2003 Posts: 97

you can only really do the big ends in situ - to do the main shells needs the crankshaft main bearing caps out, and that means you would have to slacken all the caps off in order to get them out, due to the cross-brace bolts. These pull the crankcase sides together, pinching the caps in place.

If you remove them, the only thing holding the crank in place is the front and rear Geko seals, so you would do them no good at all.

In theory it's possible, but if one of your main bearings have gone, I don't think it's worth risking it. You'll be doing it again very soon

Les

Mixsynth · Posted: Wed Jul 23, 2003 4:08 pm Post subject:

Admin · Posted: Wed Jul 23, 2003 5:53 pm Post subject:

Hi

Light tapping noise, from the drivers seat it comes from the left, and the passengers seat it comes from the right. Only there under certain combinations of revs / load. I can provoke it from about 2500rpm but I cannot hear it after 3500rpm (but then it is a P4, hardly the quietest car).

All the best

Keith

lesthegringo · Alfasud Joined: 23 Jul 2003 Posts: 97

I have to say it sounds similar to when the one I had to replace broke (big end shell).

The symptoms I got were that under no load or full load you would get no noise, but in the situation of a lightly loaded engine, like when drifting along in traffic or gentle cruise, the tapping was nice and clear. You may be lucky and it is just a big end shell broken in two pieces. If it is, it won't take long to fix it.

Les

Admin · Posted: Wed Jul 23, 2003 11:37 pm Post subject:

Hi

That is what I am hoping. A set of shells should be cheap so I will buy some and then whip the sump off. Any sign of play and I will put the new ones in which should hopefully fix it. If it doesn't then it will only have cost me a small amount of time and money.

All the best

Keith

Mixsynth · Posted: Wed Jul 23, 2003 11:44 pm Post subject:

Keith, how many miles has that engine done?
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Admin · Posted: Thu Jul 24, 2003 1:41 pm Post subject:

Hi

Not sure how old it is. The engine was 2nd hand and I cannot remember how old it was. It has done around 12000 miles in the last year.

All the best

Keith