hey all i have a piece of my head gasket missing on the exhaust side of the cylinder closest to the driver. only seems to leak when AC is running but its definately suss so must be fixed. simple question - armed with a torque wrench, lots of skin on my knuckles and probably some other stuff, can I replace my head gaskets myself? now i know there will be some time involved in getting the plenum off, then the exhaust headers, then the timing belt, then the heads, but assuming i can do all that do i have a chance of doing the gasket? I understand the z uses a dry head gasket? any advice from those in the know??? (puts flame suit on)
hey... tech says.. that the left had bank is almost impossibe but the right you can take off with motor still IN the car.. ... or was it the other way around? :bash: either way your going to wanna do both so you might wanna pull it out anyhow. best of luck... get mates and 10-15 cartons and your nearly there! :biggrin:
No need for the flame suit It depends how competent you are mechanically, it is a big job. i think it might be possible to do in place but you would need to remove the gearbox, at that stage you almost have the engine out.
Why would it only leak when the aircon is running ? The head gasket contains the pressure from the exploding fuel in your cylinders. How do You know it's leaking ? How do you know a piece is missing ? You can't see it. Oil in the coolant ? Water in The oil - grey sludge ? What does a compression test say ? If the head gasket goes, there is a reason. Changing the gasket without fixing the cause will do very little. You could have warped heads from overheating.
http://members.accesstoledo.com/mike_cain/na_cylinder_head.htm Cylinder Head Replacement, without removing the engine 1990 Nissan 300zx NA
dropping coolant! stef, today after getting fuel, i came out to see coolant under the car, it was leaking from the rear of the engine and dribling onto the ground. about one drop every second. on teh passenger side it had leaked pure water from i assume a little overflow type hose one the firewall near the passenger side header. i had had the a/c on for about 15/20 mins before. same thing happened 1 week ago in hot weather also. so in brief: coolant dropped from back of engine on drivers side, water dropped from near exhaust header on passenger side. then i got home, jacked it up and had a look. having gone home with no ac on there were no leaks, the engine was dry. however having looked at the gaskets on both sides (which i can see), i notice an area that it is missing directly below the exhaust port on the cylinder nearest the driver. also there is brown (rust colour) staining dribbing down the block, same colour as the old coolant i changed 2 weeks ago. dont get the connection to a/c other than when its hot i turn on ac, hence more chance of over heat. also engine overheated in winter after head tank broke so good chance of bad head gasket. was def. some oil in coolant when changed, though havnt dropped oil to check for coolant. oil on dip stick looks normal.. umm i thnk that all
Yes It can be done I Did it years ago, pull the heads with the turbo`s attached to the heads . be very patient and don`t bend any pipes to get them off. There is a 10 mm bolt one a head on the underside of the heads .If the part you are removing doesnt seam to come easily there are more bolts hidden there. The tech section used to have o post by Reebo but some how in changes to the Tech section Reebo`s name was changed and the post lost . ON saying that above I would pull the motor to do it next time.:zlove: :biggrin:
doesn't sound like HG to me.. more likely under plenum hose(s) leaking.. with the A/C on you'll be running a bit hotter and the hoses will be under more pressure. the oil in the coolant may have just been sludge which tends to collect in the overflow and gets sucked back in when the engine cools down.
The water dripping from the passenger side(when using A/C) is simply the moisture being removed from the air-conditioned air, and is perfectly normal(there is a drain hose on that side). There a several hoses and pipes on the drivers side rear of the engine, any one of which could be the source of the coolant leak. (See Tech Section).
Pix Hey Chilli would be very happy if it was just a plenum pull :biggrin: also i dont think there is a part of the gasket missing just had a look on ttzed at a stock gastket seems there is a recessed area below the exhaust port at the cylinder closest to driver also this z pings alot... some pix drivers side - see how stain seems to come from gasket... http://img135.imageshack.us/img135/4649/img2798ce2.jpg passenger side - cant work out what this white stuff is? gasket looks good though http://img145.imageshack.us/img145/4307/img2800kr0.jpg top side - noticed alot of staining on top of the tranny bellhousing. also on the underside of the heater pipes... http://img509.imageshack.us/img509/3192/img2803hz8.jpg hmm maybe just under plenum pipes but still keen for expert opinions!!!
Leak down hey there, atm im replacing the HG on my Z aswell. havnt removed the heads as yet-but very close. if you wanted to know if you'v got a blown HG with coolant flowing around, a leak down test wud do it or even a radiator pressure test at a garage. but it sounds like uv got oil contamination anyway. yeahh all you shud need is pretty much a torque wrench and a basic set of tools-although fancy tools like ratchet spanners make it a shit load easier. im not quite up to it as yet but apparently the hardest part in the whole procedure is replacing the head with the dipstick back on- aligning the 2 up. btw r u doing it with the engine in or out? goodluck with the repair, marlon
Again, you CANNOT see the head gasket. If it leaks coolant when stopped, you have a leak in the cooling system. Some nasty pipes and hoses at the back of the engine and under the plenum. But, yes, the cooling system could have been pressurised by hg leak, but that would have pretty much emptied the coolant while running. Do a compression test and a gas analysis of coolant.
To me the stain starts above the gasket but it's more noticeable below. I think its under plenum hose time.
Wouldn't even attempt to do it in-car for two reasons 1. With the amount of ginning around you have to do in-car it would be quicker to do the engine removal 2. With the engine out you can be more accurate, cleaner and almost guarantee a decent job,and the head bolts are angle torqued(single use head bolts, it's an engineering thing)
answers my next q baron that answeers my next q, do i need to head bolts for hg replacement. seems like yes. okay going to bight the bullet and go to a shop that can do a comp. test for me.
