Help! Blown head gasket?

dcioccarelli

dcioccarelli

Dominic Cioccarelli
Hi all,

I was driving from Munich to Stuttgart today and there is this nice stretch of road where I can normally get up to 170 Kph :) (carb 1.5L).

Anyway, I think I might have pushed the old girl a bit too far as all of a sudden she started to loose power and ping. I pulled over into the next service station and the car stalled straight away. It wouldn't really run very well at idle. I tried retarding the timing but the pinging was still there (under anything from moderate load onwards). There was also quite a bit of oil in the (after market) air cleaner (possibly coming from the crank case breather?).

Anyway, I managed to limp back to Munich (temp was ok, so was oil pressure, but pinging was there under load). Does anyone have any idea what these symptoms might indicate? A blown head gasket?

If it is the head gasket, can anyone indicate how difficult a job it is to change one. I live in the centre of the city, so I don't really have a convenient location to do extensive work. I'll probably do the timing belt at the same time, but would prefer not to have to muck around with timing marks, so if there is a technique to keep everything lined up I would appreciate it.

Cheers,
Dominic.
 
Check timing belt

I am not sure of this, but since it's easy to check, it can't hurt. Get a flashlight put the car is 4th, and hand roll it until the cam wheel pointer on top is lined up with the cam wheel mark indicating top dead center. Then check the lower crank timing mark to make sure it's pointing at the zero mark. Then check the flywheel timing mark to make sure it's lined up too. Remember, there are two revs of the crank for every one rev of the camshaft.

If the timing belt slipped, that would change the distributor timing too.
 
head casket

Hi Dominic,

If you DO need to replace the headcasket, it is not that difficult if you use all the knowledge on this formu. I did itabout 6 months ago, with help from the people on this forum and had to do the job on the street as well. Make use of the repair manual, I used Haynes, and this will lead you step by step through the process, including resetting timing etc.

Let me know if I can be of any help.

Best,

Frank
 
Dominic... I tend to agree with Mike...

Check your cam and dizzy timing first.

If you don't find a problem there... then pull the plugs, and with the throttle wide open, do a DRY and WET compression test. Further details if needed.

Post your results here...
 
Timing marks

Hi Mike,

thanks for the reply. After thinking about it, you are probably right (although I have only ever had a timing belt break on me, never slip. Anyway, better this way!).

To determine whether the static timing is out of alignment, I'll need at least 2 reference points. From this picture:

ignit1.gif


... I can easily find the top one that you refer to. But where is the bottom one? Do I need to remove the cam belt over to see that, or is it the same one used for setting the (dynamic) ignition timing (i.e. with the strobe light)?

Finally, assuming the timing is out and I need to reset it, what is the best way to do this? Normally, when changing a timing belt you need to block the engine to stop it from moving. In this case I'll need to also move it slightly. I'm assuming that when I have the belt off I just need to move the top cam pulley a bit to realign the marks, or will this also move the the bottom half? Which reference marks to I need to have lined up (I think I remember that there was a third one)?

Thanks for any pointers. I'm not at the car now so haven't had a good look around.

Regards,
Dominic.
 
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marks

Dominic,

The mark on the flywheel should align with the 0 tdc mark on the drivebelt-cover, they can be seen from the top and look like three notches, at least in my case (1300 carb).

If you have the belt removed, and align the camshaft with its mark, it will move Independent of the camshaft. So, this allows you to reset timing, but be very CAREFUL not to turn the camshaft beyond that point where it is aligned, otherwise your valves will hit the pistons at the top of their stroke causing major damage!!

The third thing you'd want to check is the ignition timing, as with the mark on the crankshaft is aligned with tdc, your rotor in the distribitur should point at the 4th cylinder

Frank
 
Non-interference?

Thanks Frank, sounds very clear. I'll go and check it out on the car as soon as the rain stops! As for the advice not to rotate the cam too much, this is indeed sound although I was of the impression that the 1500 head was a non-interference design? Or is this only the case with US cars?

Cheers,
Dominic.
 
Timing marks (where have they gone?)

Hi Frank,

thanks for the reply. I had a look at the car today but it seems that the job won't be easy. I can't seem to be able to locate the timing marks on neither the cam pulley nor the crank pulley. I took some photos (not very good quality, but the best I could do given the space).

The cam pulley shows nothing:

IMG_0711.JPG


I'm assuming that I should be looking for a mark on the side of the cam pulley which lines up with the metal pointer (above)? I'm pretty sure that I pushed the car through an entire rotation but I'll try again tomorrow.

IMG_0712.JPG


On the crank pulley, the situation is worse. Even with a timing light I couldn't see either the 3 timing marks on the yellow cover nor the mark on the pulley. The whole set-up looked different from my 1300 X1/9 in Australia so I'm not sure what's going on. It doesn't look as though there is even room to get an accurate measurement of whether the marks line up. Any pointers?

In the worst case, is it possible to set the static timing without the assistance of any timing marks?

Regards,
Dominic.
 
Agreed, but what about the smoke...

Hi Tony,

yes, I agree that timing would be the most obvious conclusion. As another issue with smoke coming from the crank case breather seems to coincide with this event though, I was thinking that the problem might be elsewhere.

By searching the archives, Steve seems to indicate that smoke coming from the crankcase would indicate worn rings (although I would have expected this to be progressive).

Worn rings would normally result in a loss of compression though (and pinging would be caused by a high compression). I will do a compression test tomorrow in any case.

Some questions:

- is there anything which could result in a rapid deterioration in piston rings? Low oil level / pressure?

- can anyone think of a link between pinging and smoke emanating from the crankcase breather?

Many thanks,
Dominic.
 
Marks

The mark on the cam pulley is just a little dimple. Hard to see.

The timing mark/pointers for the crank are seen through the P/S wheel well. IIRC, you have to remove a cover to really see them.
 
Dom... I was hopin' and wishin' the smoke thing would go away...

Do the dry and wet compression tests and then we can go from there.

But to answer your question... heat is usually the thing that will ruin the piston seal fast by usually scoring the CYLINDER walls... and that comes from lack of lube or proper cooling.

If this proves to be the case... an "Italian Overhaul in a Can" just might help... but like I said... get the compression tests done before we go there.
 
Dom...

After performing a compression test DRY... with the throttle WIDE OPEN... record the numbers for each cylinder. Cycle the test a couple of times insuring your numbers are correct. Hopefully they will record about 140 or better and be withing 5% of each other.

A WET test is where you would squirt about a tablespoon of motor oil into the spark plug hole... effectively, but temporarily sealing the rings, and then performing the compression test again.

If the compression numbers do not rise significantly over the dry test, then there is no problem with your rings. Any low compression numbers would then point to the valves having difficulty sealing. If the compression numbers do rise like 30 points, from lets say 100 to 130, then I would say you have a problem with the rings and MIGHT need an overhaul.

But... there is one more option before you have to do that... Get the test numbers first.
 
cam mark

Dominic,

I don't know if it is any different for a 1300 compared to a 1500, but my manual reads that I should align the cam pulley mark on the OUTER side of the campulley to the notch on the engine mount. There is a little hole in the yellow cover opposite of the engine mount where you can peep through with a little mirror to check for the mark on the pulley.

In my case, this mark on the outer side of the pulley is more clear and a definite circle, whereas the mark on the innerside that should align with the metal pointer on the picture is less clear.

Don't know why they have two marks, but maybe in your case you only have the outer one.

Hope this helps!

Frank
 
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1500

My 1500 is a interference engine and is unmoded so do not assume anything and be careful when turning motor as not to bend valves.
 
Compression results are in.

First of all, let me say that my compression tester is not particularly accurate (not the screw in type), but I guess the figures will give a rough idea of the problem.

1 Dry 130 PSI Wet 195 PSI
2 Dry 120 PSI Wet 170 PSI
3 Dry 145 PSI Wet 150 PSI
4 Dry 50 PSI Wet 90 PSI

So it looks as if there is something wrong with cylinder 4 (plus maybe rings on all cylinders). Question is what would cause such low compression? Valves or rings? There is some difference between the dry and wet results, but it is not huge.

Thoughts?
 
Usually adding some oil for a "wet" compression test improves the readings by sealing the rings, and has little effect on the valves.

A leakdown test will help determine the precise problem, though it looks like you're losing quite a bit past the rings, and something else may be wrong on #4.
 
Compression loss

Hi Greg,

yes, I realise that the wet test is to check the rings. I think that the rings were never very good on my car, but I'm really trying to figure out what happened in the "sudden event" when my car slowed down and started ping and idle roughly as I was driving to Stuttgart. Rings would be a progressive failure I would imagine (I did not overheat).

I'm suspecting something to be wrong with cylinder #4. Either a blown head gasket there (hopefully) or a hole in a valve...

Cheers,
Dominic.
 
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