Guest Anonymous Posted August 2, 2001 Share Posted August 2, 2001 I knew my z (77 280) was using oil a little and had a tiny bit of smoke when cold.. but today i filled up at a gas station that i dont usually go to... it was a cheap ass station too.. but anyway a few hours after when i started driving my car again i noticed white smoke billowing out the back. it was never visible from the car before... at first i thought watered down gas... Now it appears to have a bluish tint to it (oil)... gould the gas have caused a rapid downturn of the situation with the burning oil? Also my valves seem to be tapping pretty loudly now as well... it may have just gotten worse over time... Any advice? I was thinking of throwing an 82 turbo in.. would this be a good time? thanks Quote Link to comment Share on other sites More sharing options...
Drax240z Posted August 2, 2001 Share Posted August 2, 2001 Well start by checking your oil level and pressure. Bad gas wouldn't cause 'billowing'... Things to check for: -overly rich fuel mixture -timing retarded too much -fouled spark plugs -loss of coolant due to headgasket leak Any of these things will cause the car to smoke a lot... If you are sure its oily smoke (blueish) then chances are you've got some bigger internal problems, and its time to think about a rebuild or swap. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 2, 2001 Share Posted August 2, 2001 the oil pressure is about 15-20psi at idle and about 45-50 when driving. The oil is right between the two marks on the dipstick... How do i Check for rich mixture on an fi engine... the smoke isnt black so i dont think that is the problem. How do i check timing also... I will check plugs tommorow I guess.. and i think the coolant is fine. Thanks Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 3, 2001 Share Posted August 3, 2001 well, I checked the plugs and cyl. 1-4 are very clean... 5-6 are either lightly oil fouled or carbon fouled... Someone suggested that I had blown the headgasket and this is what he said would happen... Sound right? I think I want to rebuild or get a turbo engine so... What is involved in the rebuild do i need new pistons? what do I need and how much should it cost. is it a good idea to rebuild when the headgasket blows? After work I will check the plugs to make sure that is what happened. Fraga Quote Link to comment Share on other sites More sharing options...
Drax240z Posted August 3, 2001 Share Posted August 3, 2001 Fraga my headgasket went on my 260z about 3 weeks ago. Do a compression check first, and see what your readings are. If you have one cylinder that is way lower than the rest, or 2 right next to each other that are way lower than the rest, you might as well pull the head. Its not too large a job to do the headgasket really. Took me 4 days to do mine, but the only tools I had were a swiss army knife and a leatherman. Seriously. You should be able to do a headgasket swap in a day without too much trouble. Probably best if thats the problem to get your head surface planed to true it up as well if thats the problem. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 3, 2001 Share Posted August 3, 2001 thanks, what is a good gasket to get? I may look into a turbo motor so it doesnt have to be great for this one... Also, my dad said you have to tell the insurance co. if you swap motors and that my insurance would go up... is this true? oh, I forgot... could the rings be ok and the engine still burn oil... like oil blowby if the valves are way out of whack? Fraga [ August 03, 2001: Message edited by: Fraga280 ] Quote Link to comment Share on other sites More sharing options...
Drax240z Posted August 3, 2001 Share Posted August 3, 2001 It could be valve seals. A compression check should be able to tell you that. I used a fel-pro headgasket. It was about $30canadian. No idea about insurance in the US, have to talk to some of the other guys here. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 3, 2001 Share Posted August 3, 2001 At one time I owned a 280ZX that developed a head gasket leak. At the suggestion of a salty old mechanic I bought this product called K&W Block Seal. It worked beautifully by following the directions EXACTLY: Change the oil first (if it has any water at all), drain and flush the cooling system, refill with fresh water and burp out all the air, remove the spark plug from the affected cylinder(s)(critical step otherwise engine compresion will blow the stuff out), add the block seal to the cooling system, and run to operating tempature (cardboard in front of the radiator will speed this up a little, make sure you remove it soon after it's warm). This will be LOUD so do it in the daytime and away from bedroom windows. As the cooling system pressurizes the sealer is forced into the voids of the cracked engine or head gasket, where heat fuses it in place. The car ran for over 1 year till selling it. Just a thought if you do have a crack or blown head gasket. [ August 03, 2001: Message edited by: PARAGOD ] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 3, 2001 Share Posted August 3, 2001 paragod, thanks for the tip... may try that for now cuz this damn smoke is an embaresment to z's... Also, I dont have a gauge to check comp... which type do i need... just a screw in air pressure gauge or what? Thanks.. sorry for my ignorance.. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 3, 2001 Share Posted August 3, 2001 whoops.. double post. [ August 03, 2001: Message edited by: Fraga280 ] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 3, 2001 Share Posted August 3, 2001 Head gaskets are easy jobs, and fel-pro are good gaskets. But if you do not take the head bolts out and put them back in a certain sequence, you risk warping the head. Also, get new bolts, most are one time use only bolts, once used, they are stretched and the threads will stretch when the bolt is extracted. I suggest ARP bolts, they hold really well and I've yet to snap one (I use them all the time). Make sure you get grade 8 or higher, anything less than that would be too weak. I'm asuming you have the stock straight 6, so I'll give you the loosening and tightening sequence. It is as follows: 12 8 4 2 6 10 14 11 7 3 1 5 9 13 Bolt 12 and 11 are at the front of the engine. Remove and install bolts in same order. starting with removing #1 working your way up to 14. There is no removal spec. other than pattern, but installation is different. Depending on year, you have torque specs. to follow. They are as follows with model years and engines: '70 - '71: 2 steps on each bolt: 1 - 33 lbs. 2- 47 lbs. Torque all bolts in pattern to step 1, then torque in same pattern to step 2. '72: First step 47 lbs., second step 55 lbs. 1973: 3 steps. 1. 30 lbs. 2. 44 lbs. 3. 54 to 61 lbs. 1974: same as 1973. 1975 - 1983: same as 1973-74. 1984-86: 40 - 47 lbs. in one step. Best to make it two steps, one to 20 then second to about 45. USE A TORQUE WRENCH! This is not a time to screw up and use just regular hand wrenches while guessing what kind of force you are using on it. Intake and exhaust bolts and nuts are as follows: 1970 to 1974: 5.8 - 8.7 lbs. 1975-83: intake bolts 12-14 lbs., intake nuts 17-20 lbs. Exhaust: 13-16 lbs. 1984-1986: two steps for all. step 1: 10-12 lbs. step 2: 28-33 lbs. Camshaft sprocket bolt: 1970-1972 36-43 lbs. 1973 86-116 lbs. 1974-83 94-108lbs. 1984-86 58-65 lbs. All of the above are once step for camshaft sprocket bolt. Don't forget to unhook everything that is in your way and then make sure you put it back in the exact spot. Label your plugs, wires, bolts, everything!! Don't mix up headbolts, they are all different sizes and if you intend to re-use the bolts, you better keep them organized, so don't just toss them in the coffee can on the side. Be careful with this job, it may seem easy, but if you screw it up, you'll pay for it. Also, change your oil and coolant when your doing this. You're better off draining it all out and filling everything else back up when done. Also, mark your timing chain and sprocket so you don't lose the set time. It's about an 8 hour job in the Nissan books, if I remember correctly. I got all the above info from an ancient Chiltons manual, which would be a wise investment for this project. It's worth the 15 bucks, trust me. Oh, and a simple fix if you need it to prevent burning more oil. Change you PCV valve. If you have a stuck valve, pressure will back up in the crankcase and you will lose seals this way. The pressure will eventually force its way through gaskets, even rubber, steel, and cork gaskets. Also, you mentioned cheap fuel. Take a sample to a local shop and find out about getting it analyzed. If the fuel caused the problem, you get all your repairs done for free. The station is legally liable for selling bad fuel and the reprocuscions. Check with a good mechanic to verify that. One interesting fact that will make you dig through the law books. Where I am, in Tennessee, legally there can be 10 inches of standing WATER in the bottom of the fuel storage tanks at the stations that are below ground. Make sure you get a sample and have it analyzed though. Take the station to court if you have sufficient evidence of selling bad product that could cause automotive damage. It'll pay off if you can get the station to pay your bills. I might have left something out, but if you have any questions, just email me. PenguinsHurtMe@aol.com. Good luck with the project. Oh, and yes your insurance will go up if you do the engine swap. But who says you absolutely have to tell the insurance? As long as you don't wreck the car, they have no evindence. Changing the block vin plates would be a good idea in this situation, but that is a crime in certain areas so watch your step. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 6, 2001 Share Posted August 6, 2001 When I do the head gasket should I get new intake and exhaust gaskets as well, or just use the old ones again? Thanks Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted August 6, 2001 Share Posted August 6, 2001 You may not have to take the intake and exhaust off of the Z to do a head gasket since they are all attached to the head (though it would make it easier). Just do yourself a favor and spend the extra 5-6 bucks on the intake/exhaust gasket...just in case. If you do remove the old one, it will be "junk". *IMPORTANT* Just make sure that you have a piece of soft wood (or proper tool) to jam the timing chain in place before removing the camshaft gear. The timing chain tensioner will draw your timing chain down into the front cover and when you go to put the head back on, all of a sudden your timing chain will be too short!! You'll turn a few hour job into a 2 day job...made that mistake ONCE!! Have fun!! Mike Gadwaw orlando, Fl Quote Link to comment Share on other sites More sharing options...
Drax240z Posted August 6, 2001 Share Posted August 6, 2001 Just an addendum here. Try to find a piece of hardwood for a cam chain tensioning wedge, either that or order the piece of plastic that MSA sells (for around $10 I think) for that job. Soft wood can splinter a bit, and generally you don't want wood slivers anywhere in there. I managed to do mine without taking the carbs/intake or exhaust manifold off the head. Just lifted it all out as a unit. Probably best to have 2 people when you go to do that. I did it alone but it was a bit of a struggle lifting head/intake/exhaust in and out while leaning over the 2 feet to get over the fender. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 7, 2001 Share Posted August 7, 2001 well, finally did a compression test... Dry-cylinder #6-170 #5-165 #4-145 #3-145 #2-145 #1-150 Wet- #6-170 #5-165 #4-175 #3-170 #2-170 #1-170 Could this be just the head gasket or the rings and or valves too? Thanks... Quote Link to comment Share on other sites More sharing options...
Drax240z Posted August 7, 2001 Share Posted August 7, 2001 Doesn't look like your headgasket. Compression is much too high. For example, when mine went last month my compression check from 1-6 yielded: 125/125/125/125/125/45 It was pretty obvious #6 had blown the headgasket. (lots of white smoke, loss of coolant, etc) From your wet results, it looks like your rings are going. THe large jump from dry to wet in cylinders 1-4 would indicate rings more than anything else, and this would definately explain your oil burning problem. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted August 7, 2001 Share Posted August 7, 2001 I agree with Drax, it looks like rings could be your beef. If you don't mind rolling around in a bit of oil, they can be changed with the engine in the car. You have to raise the engine slightly to remove the oil pan, but it can be done. Pax, Mike Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 7, 2001 Share Posted August 7, 2001 Could it also be the headgasket? becuase the three cylinders with the lower compression were very clean... I am looking into gettin a whole turbo car for the engine, should I just wait and not rebuild this one? How much should it cost to rebuild and what has to be replaced? Thanks Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted August 8, 2001 Share Posted August 8, 2001 Although they were low, they weren't significantly low. If you look at Drax's #'s, that is what you would expect if a head gasket is blown. Also the "wet" test shows the tell-tale rings not sealing. Again, it depends what you need to do. If this is your primary transportation, you could take a day and replace the rings w/ the engine in the car. If you have other means, you could pull the engine and rebuild it. You could pick up another engine and have work done to it. It all depends on how fast you need the car running and how deep your pocket book is. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 8, 2001 Share Posted August 8, 2001 You can do a leak down test to see where the leak is in a cylinder. Basically its a air fitting that screws into your sparkplug hole. The cylinder is loaded with air pressure, then you take a mechanics stethescope and listen in a few areas. Those being, the valve cover (bad valve will cause the air to leak here), Dipstick tube (Bad rings will let the air leak into the bottom end and you'll hear it here the best) and Radiator, this is a visual, if its leaking into the water jacket you should see some bubbles in the radiator. If its a head gasket it can also leak yet not be into the water jacket, if thats the case running the stethescope around the parameter of the head should give you a clue where its blown. Thats just another way of eliminating what it might be, not expensive to do either. Good luck with it, hope you find it without to much trouble. Regards, Lone Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.