Blown Head Gasket!!!

[NickF]

Have you checked the tappet clearance??

If far enough out car can behaveas described.

Nick

[Gav240z]

No i hadn't yet Nick I had left the car a whole week not wanting to drive it because I had planned a tune valve adjustment and oil and filter change.

I needed it that weekend to make it to a my University expo day because I was interested in a mechanical engineering course and was gonna find out about it talk about bad luck :stupid: .

Anyway I have bought a feeler blade and valve cover gasket in preperation for it but had never got around to it.

My theory on what happened is something like this.

I noticed the dizzy rotor button and cap were fairly worn out and there was a build up on the middle of the rotor button that may have influenced poor ignition.

The carbs were running rich and in traffic it fouled up and caused the car to backfire thru the carbs possibly from the valve clearance.(causing the bang I heard) then the smoke out the intake.

So far so good I drove the car around yesterday all day and replaced rotor button leaned off the carbs on both sides half a turn car seems a bit nicer to drive aswell. I have to still get dizzy cap it's got new spark leads and plugs also.

The compression seems ok and no water has been lost.

for the water out the exhaust it had rained in between trying to get the thing started again and calling friends to pick me up or give me ideas on what it could have been.

This could be the cause of the watery exhaust because the exhaust points upwards into the air out the back of the car.

The car cutting out could have been ignition or just getting too fouled up and choking.

I still would like to pull the head replace valve stem seals possibly inspect anything and look into a more aggressive camshaft profile.

I have holidays in a week so it will be a good time to do some catch up maintenance.

[Gav240z]

new update!

Ok so i'm driving along to a friends house and as I turn into his street I notice the tacho is dead and the engine has completely stopped.

I let it roll down the street towards his house.

Stop and try and start nothing just turns over

it's very cold and I get out and use the famous inspection lamp thanks Nissan . I remember someone saying to check the distributor connection but nothing, fuel doesn't seem to be an issue.

I've recently replaced the rotor button and the distributor cap looks worse for wear and could be the issue here.

Tried turning the engine over for ages no luck what so ever, I don't like it's leads or spark plugs at all. The fuses are all good is there anything under the dash that could cause the car to just cut out? a fusible link??

I'm completely stumped, not to mention the car was in similar cold weather on the day it happened as it was tonight so i'm not sure if that's anything to do with it.

Help.

[Zedrally]

Gav,

Have you been following the Alternator, Condenser, Ideas thread?

You both appear to have similar problems, perhaps all is in the capacitor.

I had a similar experiance, possibily worse as the engine idled OK but cut out under load.

All was traced back to the cap. IN this case it had a break in the little wire and would be intermitent in use.

MOM

[Gav240z]

No I haven't which capacitor are we talking about? There is none on the side of the dizzy because it's electronic, I'm hoping it's not the black little unit on the side of it there worth a staggering $800.

The rotor cap is pretty shot hence the reason I was trying to chase one the other day. I think the new rotor button was less worn and was able to extend that bit futher to the points in the cap and therefore the reason the car hasn't played up.

I will try locate the thread you are talking about.

The alternator seems fine I had plenty of charge in the battery I turned the car over and over and over.

However I did notice while driving the AMP meter was in the positive direction something i never took note of before???

Hmmm.

[Gav240z]

Note car does not idle either . I could not even get it started again last night.

This time it just died no bang no coughing just died and would not start back up.

Thanks for the help also.

Gav

[Zedrally]

HAve you checked for spark?

[Gav240z]

No Mike but i do plan on doing it, I was too scared of the shock I might receieve through the crappy Top Gun leads if they decided to go to the easiest path of flow and Zap me again.

I have rubber gloves at home and I was at my mates place, I left the car there for now.

I felt all 250,000 volts last time hehe cause the lead was of poor quality and was trying to get it to sit on properly.

Anyway I'll keep you updated I have a feeling that it could be the distributor it self I hope not.

Not alot can really go wrong with them, the coil is a new model bosch unit.

So is there a condenser on the electronic dizzies?

Or were you referring to the points type?

Also do dizzy caps between electronic and points type interchange I have a spare dizzy cap at home but I think there different would you know?

[my_mad_z]

Gav, when you rang me, you didn't tell me you heard a loud bang! I had a similar problem twice in one day, but it's not the same problem as yours; I snapped the cam shaft and it ran on 1 cylinder for a couple of seconds then bent the hell out of a few valves! I fixed it on the side of the road (at the front of Waz's place) and had it running after 4 hours. 10 min later, bang, cam snapped again! Turns out I had two threaded bolts that hold the cam to the head that caused it to snap.

Another time I heard a bang was when I foolishly revved the L26 off the tacho....... never ever do this! I heard a big bang and then puffs of smoke spewed out of the exhaust. When I stripped the motor, all the piston rings were broken! Funny thing is, it still ran for two weeks. Now before you all think I was mistreading my Z, I was planning on fitting an L28 and I wanted to see how hard the L26 would rev. Stupid thing to do, I know.

I came across a similar problem in another make of car and I diagnosed the problem to be the dizzy cap and rotor button. If they are excessively worn, the car will run like a pig. Try changing them and if you're questioning the leads, change them too. If you have good compression and you're not losing oil/water, then it's definately not the head gasket. The water coming out of the exhaust is would be condensation forming in the pipes. I'm not sure why it's only coming out of one exhaust though! As for the bang, not sure what that would have been, hope it's not the same thing as what I had with the L26.

If you can get the Z to my place, you're welcome to try parts off my Z to see if you can sort out the problem. One other thing, have you checked to see if the distributor shaft is bent?

Let me know if you want to bring it to my place.

Marc.

[Gav240z]

Thanks for the help Marc as always I appreciate your help, the bang I have put down to backfire as it wasn't a big bang but it all happened so fast and long ago it's a bit of a blur.

The smoke out the front of the intake made me think headgasket as I remember my mates HOnda .

The exhaust and the water residue to one exhaust only can be easily explained because it was out of tune and one carb was doing more work I'm sure you understand.

This time last night when it went dead I just turned into my mates place and it just rolled no bang nothing.

It cranks but no action, the dizzy cap is worn bad I used a key to scrape alot of crud off it and have bit of the metal chip away.

I don't know of any condensers or anything that could be gone, funny thing is it when i turned into my mates street I looked at the tacho and saw it wasn't working then I tried to rev the car and it all went dead.

Now it's a bit hard to remember exactly if the engine was running with no tach working but I'm pretty sure cause you know how loud my car is.

Because the tacho is wired thru the ignition I think it's something in that area but what? i don't know as I've said in the past the electronics side of the car is the one part I'm not good at.

I think things like this will help me learn though .

I'll try get a dizzy cap soon and try that after that though no ideas thinking something under the dash :disappoin

[Zedrally]

Originally posted by Gav240z

So is there a condenser on the electronic dizzies?

Or were you referring to the points type?

Also do dizzy caps between electronic and points type interchange I have a spare dizzy cap at home but I think there different would you know?

Dizzy caps are different,

Had problems with Electronic Dizzies, so I chucked it out and went back to points.

[my_mad_z]

If the tacho went dead and the car stopped, it's more than likely that you're problem is in the dizzy. The Z will not run without the tacho in place and more than likely you are losing spark in the dizzy. Pull of one of your leads while the engine is off, hold it 2-3mm away from the rocker cover and crank it over to see if you're getting spark. If not, try the coil lead by doing the same thing. Just be carefull, cauz I've heard the modules don't like it when you do this. If it shits itself, I've got 3-4 spare lying around, so don't panic. The best place to get parts for the electronic dizzy is pick-a-part. $50 will get you a complete dizzy! That's if they're available. They're the first thing to go when a Z or an early skyline get wrecked a pick-a-part! I'm almost certain that you're problem lies in the dizzy. Sorry if this has already been mentioned earlier in the forum, I didn't have much time to read everyone's response to your problem. Anyway, good luck and I hope it works out well.

Marc.