Alfa Pages

micap · Alfasud Joined: 14 Mar 2003 Posts: 62 Location: Denmark

Hey folks

Got my new waterpump in today, and of course that meant new cam belts as well. I got the timing right, but the car seems to shake quite a bit now when accelerating from low revs. Can this have anything to do with the cambelt change? I noticed too, that the left camshaft was a lot harder to pull around than the right one, any idea why that is, and if it relates to the shaking?

Thanks in advance
Michael
_________________
/Michael

ex 89 1.7 QV
now 85 1.5 QV with 1.7 engine.

Admin · Posted: Fri Mar 14, 2003 9:25 pm Post subject:

Hi

I would double check the cam timing. My father had a 33 where a main dealer fitted new cam belts, but were one tooth out on one bank. The car ran OK but was not smooth (and he ran it like that for some time Rolling Eyes

)

If the cam timing is OK then I would check the compression. You mentioned that one of the cams was more difficult to turn. You should not turn the cams when changing the belts. If you turned a cam with the engine at TDC while changing the belts then it is likely to bend some valves.

Lastly, was the battery disconnected while the belts were being done (I do this just to ensure I do not make a mistake and try and start the engine)? If so the ECU memory on a late car will be cleared and it will take some time for it to relearn the settings from the lambda probe (or in my case last time, the lambda probe was not working so the car continued to run badly)

All th best

Keith

micap · Alfasud Joined: 14 Mar 2003 Posts: 62 Location: Denmark

I'm positive I got the timing right, since I made some marks on the pulleys before I took the old cambelts off. I mean, if the belt is one tooth off, it will clearly not fit to the mark I made, but they both fit perfect.

Any easy way to check the compression? This is a sign of a broken head gasket right? I am a bit concerned since there is quite a bit of oil at one of the heads.

And btw. it couldn't be the ECU since it's a carb model.
_________________
/Michael

ex 89 1.7 QV
now 85 1.5 QV with 1.7 engine.

Guest · Posted: Sat Mar 15, 2003 12:46 am Post subject:

it can be easy to tell if the cam timing is wrong

the engine will sound offbeat kinda like a subaru
not nice and crisp like an alfa..
check also your engine mounts

Adrian (melb) · Alfa Arna Joined: 15 Mar 2003 Posts: 10

checking the compression is easy. you need to, disconnect the ingintion coil, take out a spark plug put in a "compression tester gauge" turn the engine over with the throttle fully depressed. Take reading and replace spark plug. If all the cylinders are the same then all is well (a good engine reads 170-180 psi, a slightly worn engine reads 130-150 psi) but dont be too concearned if it is a low reading the most important thing is that they are all roughly equal.

Cheers
Adrian 86 QO (1.7ti)

micap · Alfasud Joined: 14 Mar 2003 Posts: 62 Location: Denmark

It sounds exactly like it used to do, so I'm sure I got the timing right. It idles and revs perfect when standing still, it's only when accelarating the shaking is noticeable. I will try to clean the carburettors.
Any easy way to check if an engine mount is broken?
_________________
/Michael

ex 89 1.7 QV
now 85 1.5 QV with 1.7 engine.

Admin · Posted: Sat Mar 15, 2003 3:00 pm Post subject:

Hi

Strange that. I cannot think of much that would cause problems for the engine at speed but not at idle. Is the shaking related to engine speed? At what revs does it appear? Does it continue to get worse?

It is possible that you would bend a valve, but I would think this is most likely to cause problems at low revs rather than high revs.

I would check all the little things that are easy to get wrong or disturb when doing the belts. Check the plug wires are secure and going to the correct plugs, that the fuel pipe hasnt been kinked, that the vacuum pipe for the distributor is in place and that any fuel filter is clean enough

By the way for future reference the cams are marked so that you can check they are in the correct position on the hydralic tappet engines (the mechanical tappet ones you have to take the rocker covers off). There is a small hole on top of the cam pulley wheel (normally filled with a rubber grommet). When the cams are in the correct position then you should be able to see one tooth central in the hole with a small V shaped cutout in the dips either side of the tooth.

All the best

Keith

micap · Alfasud Joined: 14 Mar 2003 Posts: 62 Location: Denmark

The shaking only appears at low revs, like when accelarating from 1500-2000, and then dissapears in higher revs.
I am now certain that I have a broken head gasket, since there is a milky substance on the fillercap. How bad is it to drive around with a broken head gasket? And how much would it cost to get fixed? How much time does it take? I don't think it's a job I'm capable of doing myself.
_________________
/Michael

ex 89 1.7 QV
now 85 1.5 QV with 1.7 engine.

Admin · Posted: Sat Mar 15, 2003 7:51 pm Post subject:

Hi

Do an oil change and clean it all out, and then see if the white goo appears again.

If you are capable of changing the cam belts then that is the most difficult part of doing the head gaskets

It took me quite a while to do them on the drive, but then I didnt spend as much time working on it as I should have done. Get all the gaskets and tools and it should not take too long. The Alfa tool for doing the head bolts makes the job far easier to do without taking the engine out.

If you run the car with a leaking head gasket then you risk a few problems. The oil with water will not lubricate very well. It is likely that the gasket will fail dramatically at some point resulting in serious overheating. This can lead to warping the heads. Also a small amount of hot water seeping through the gasket under preasure can damage the head

All the best

Keith

micap · Alfasud Joined: 14 Mar 2003 Posts: 62 Location: Denmark

I changed the cam belts myself, but I can't see how I'm supposed to change the head gaskets with the engine in the car. What kind of special tools do I need?
_________________
/Michael

ex 89 1.7 QV
now 85 1.5 QV with 1.7 engine.

Admin · Posted: Sun Mar 16, 2003 4:56 pm Post subject:

Hi

It is not that difficult. Remove the exhaust front section, remove the cam belt covers and belts, and remove some parts of the fuel system (I think it is easier to just remove the carbs, but not sure it is necessary)

The heads are held on with 6 long bolts on each side. I dont think you can remove the bolt from the heads with the engine in place, but that does not mattter. You undo the bolt (17mm socket I think) and then just remove the complete heads with the bolts still in place. On the 8V you do not need to undo any engine mounts.

The Alfa tool that makes it easy is basically a 17mm socket attached to a bar with a 1/2" drive square at the end. It means that you have the space to use a torque wrench on each of the bolts. It looks like this:-

All the best

Keith

micap · Alfasud Joined: 14 Mar 2003 Posts: 62 Location: Denmark

Ok, doesn't sound very complicating at all. Is it be necessary with the special tool or does it only make it easier? Would I be needing any parts other than a new gasket?
_________________
/Michael

ex 89 1.7 QV
now 85 1.5 QV with 1.7 engine.

Andricus vd Westhuizen · Guest

Check your inner CV joints for wear! This normally shows up under power, with the car running smoothly when "coasting".

James Granger · Alfa 33 Joined: 10 Apr 2003 Posts: 302

Shouldn't the heads be skimmed as well?