ferrariowner123 Posted March 25, 2014 Share Posted March 25, 2014 (edited) So a little back story... My dad and i have starting making our local rally that we go on, a tradition, the first year we didn't have a special car, but last year we bought this 1977 Datsun 280Z, and we took it out to the rally last year, well its getting close to that time of the year again and its been giving us some problems. For almost 2 years now, its had an interior coolant leak that i have been battling ever since we figured it out what it was. We finally ponyed up and replaced everything, Bought a rebuild heater control valve, all new hoses, and a rebuilt heater core. Installed all of that and seems to be leak free After getting it all sorted, i started up, had to bleed the cooling system, i left the heater valve closed (on the cold setting on the dash). I let the engine warm up to get the thermostat open and get coolant in the engine. When i got up to temperature it starting gushing coolant out the radiator (i left the cap off the radiator while it was warming up) i promptly opened the hater valve and it sucked up the coolant. However, while arguing with my dad to keep him from taking the car out (he has the equivalent patience level of a 5 year old) so that i would have to time to check everything and insure that everything was installed correctly, i took a peak at the oil pressure gauge which always sits around 40-50ish PSI while idling, was reading just a hair over zero. I have no idea how long it was reading zero, so i turned off the engine, checked the oil, assuming that it was just low (has a fairly good oil pain leak). After checking, it was at a good level, but but VERY watery like in its consistency. like it was dripping off the dip stick. It was still very black (needs to be changed) so not chocolate milk, which is what is always described when coolant mixes with oil, so i'm not sure what it is. Do i need to pull the head and see if the head gasket failed? I'm going to change the oil get the car back together from changing the heater core. and let it run for a bit, check the oil. Is that a safe plan? i have no experience with something like this so i was hoping to get some help!! Rally is coming up soon and i need to know if the head needs to be rebuilt. Thanks for the help. -Kyle Edited March 25, 2014 by ferrariowner123 Link to comment Share on other sites More sharing options...
5523Pathfinder Posted March 25, 2014 Share Posted March 25, 2014 Might want to run down to the local parts store and get a block tester. It will tell you if the head gasket is popped. Might be worth pulling the plugs and inspecting each for fouling to find what cylinder has the issue. Yes, change the oil before you run it anymore. Link to comment Share on other sites More sharing options...
kdj Posted March 25, 2014 Share Posted March 25, 2014 Your plan sounds right. Change the oil and filter and make sure the rad is topped up and the over flow is at the right level. Let it warm up if the oil pressure is up. Then check the levels again to see if either has changed. The coolant level might drop if there is still some air in it but the oil level shouldn't. I hope your head gasket is O.K. that's a nice looking car. Link to comment Share on other sites More sharing options...
silverton Posted March 25, 2014 Share Posted March 25, 2014 If you had a blown head gasket you'd have geysers coming from the radiator even while cold. What did the oil smell like? I'm thinking it got saturated with fuel. And if you run Royal Purple in it, I recommend you stop. Link to comment Share on other sites More sharing options...
ferrariowner123 Posted March 25, 2014 Author Share Posted March 25, 2014 Might want to run down to the local parts store and get a block tester. It will tell you if the head gasket is popped. Might be worth pulling the plugs and inspecting each for fouling to find what cylinder has the issue. Yes, change the oil before you run it anymore. Had to check what a block test was, is it the same as a leak down test? ill check the plugs tomorrow If you had a blown head gasket you'd have geysers coming from the radiator even while cold. What did the oil smell like? I'm thinking it got saturated with fuel. And if you run Royal Purple in it, I recommend you stop. Okay good to know, it was gushing water right when it got up to temperature, but once i opened the heater valve it stopped. and the oil smelled like oil? is it possible that it just went "bad" after sitting for so long with hardly any use? ill post and update tomorrow. -Kyle Link to comment Share on other sites More sharing options...
5523Pathfinder Posted March 25, 2014 Share Posted March 25, 2014 No, a leak down tester is different. It goes I place of the spark plug, you close the cylinder to TDC and apply air. If there is a leak, it will push air into it and you can hear it out the intake, exhaust or bubbles in the cooling system. A block tester goes on top of the radiator, you pour a special liquid inside and run the engine. The tester usually has a small hand pump and you put a slight vacuum on the cooling system to pull any combustion gases into the tester. If gases are in the system, the special fluid will change color. Link to comment Share on other sites More sharing options...
silverton Posted March 25, 2014 Share Posted March 25, 2014 Oil does break down over time, that's why a time span, 3 months or whatever?, is also stated on oil change intervals. Link to comment Share on other sites More sharing options...
ferrariowner123 Posted March 25, 2014 Author Share Posted March 25, 2014 No, a leak down tester is different. It goes I place of the spark plug, you close the cylinder to TDC and apply air. If there is a leak, it will push air into it and you can hear it out the intake, exhaust or bubbles in the cooling system. A block tester goes on top of the radiator, you pour a special liquid inside and run the engine. The tester usually has a small hand pump and you put a slight vacuum on the cooling system to pull any combustion gases into the tester. If gases are in the system, the special fluid will change color. Interesting, never heard of anything like that, got my fact for the day!! if the oil change fixes the problem, then ill call it good, but i may add a block tester to my arsenal of tools some day... hopefully not for this car... Oil does break down over time, that's why a time span, 3 months or whatever?, is also stated on oil change intervals. Okay, because i checked the oil in my drain pan and it was fine, no signs of gasoline smell. Smelled like old oil... but now thinking about your gas soaked theory, this car does have a pretty awful smell if you are behind it, smell of fuel, and it appears to have different injectors (old owner install i'm assuming) so maybe the engine is getting too much fuel? but how does that translate to soaked oil when it appears to be running fairly well? it doesn't bog, has tons of torque, and starts fairly easy every time? But i will say that the last time the oil was changed was around a year ago and the car had maybe been driven 1000 miles in that year (she truly is a garage queen). The oil was VERY black that came out and i replaced it with the same stuff that went in, Costco box of Mobil 1, full synthetic 5w-30. I guess if this checks out than i guess we just need to be more strict with our oil changes, put some cheap stuff in over the winter, drain it before summer starts and put some nice synthetic back in for the summer and repeat? i do know that you are suppose to change the oil before putting a car into storage for a few months (which we didn't), and add fuel stabilizer, which we didn't do... But i will say that i learned alot from this car, hopefully we can keep her running for a long time. Thanks for the help guys, i changed the oil last night and i have yet to start her up, im going to go do that now and see if we get some oil pressure, ill post back with results before the end of the day... -Kyle Link to comment Share on other sites More sharing options...
silverton Posted March 25, 2014 Share Posted March 25, 2014 Mobil1 is an excellent oil! But it being 5w would attribute it to having the consistency of water. Oddly enough oil numbers are weird. the first number is cold viscosity, and the second number is hot viscosity. the W stands for Winter. Link to comment Share on other sites More sharing options...
ferrariowner123 Posted March 25, 2014 Author Share Posted March 25, 2014 yeah, i just stuck the dip stick in the fresh oil and it acted the same, forgive my ignorance on this, i really have no experience with highly focused engine work beyond basic maintenance. But i went and took a look at the plugs and again, no idea what i'm really doing here, so if you could tell me what i'm looking at that would be great... But after changing the oil, it started to build oil pressure got to about 40-50 ish on the gauge, and then as it got warmer slowly started dropping, but i have no idea on how accurate that gauge really is. i need to go out and get a cheap orielly one, it would probably be easier to read and more accurate than the 36 year old one in there. But what else, it sounded exactly the same as always and was running fine, gave it some revs, no blue smoke, but plenty of white smoke, i just figured that was because it doesn't have a cat? but it was no more than normal or before all of this... -Kyle Link to comment Share on other sites More sharing options...
silverton Posted March 25, 2014 Share Posted March 25, 2014 My Impretza is constantly belching white smoke (when ambient temp is low'ish) and my assumption is also because it is cat-less. Those plugs look EXTREMELY old. Like 100,000 mile copper old. As far as oil pressure, it's probably fine as long as the needle is hanging out in the middle of the gauge travel. If the pressure runs low I'd just recommend changing the oil out for a 10w30. Washington is mild enough that 5w isn't really necessary. Link to comment Share on other sites More sharing options...
ferrariowner123 Posted March 25, 2014 Author Share Posted March 25, 2014 (edited) Plugs were changed last year... And as far as the oil gauge travel, ill just take a picture, its easier just to show you... Here is the gauge off And here is what it got to during warm up right after the oil change, and then slowly started to drop. -Kyle EDIT: does going up in oil weight affect the pressure at all? i have a ton of Mobil 1, 10W-30, but i have run 5W for a while, why am i now seeing a pressure issue? Edited March 25, 2014 by ferrariowner123 Link to comment Share on other sites More sharing options...
5523Pathfinder Posted March 25, 2014 Share Posted March 25, 2014 Well, oil pressure should change depending upon engine revs and temp. Should be a bit higher when cold, but may drop when warmed up at idle(that pump ain't moving very fast). Your plugs defiantly look a bit fouled. A new set might not hurt. Looks if you do have some oil burning, and may be running a bit rich, but not terrible. I would be more worried if they had some whitish/yellow deposits on them. But, if it's just starting to go, it may not of built up yet. Pop some new plugs in it(make sure they are gapped right), start and run engine with the heater on and let her warm up. Do you have a attached funnel on your radiator for filling? This would help burp the system of any air that may be trapped from changing the heater core. Once it's warmed up, look for some gasing from the radiator and smell it. If it smells like exhaust, you got a problem. Coolant funnel... http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Radiator-Funnel-Kits/_/R-SER774000_0405868358 Link to comment Share on other sites More sharing options...
ferrariowner123 Posted March 26, 2014 Author Share Posted March 26, 2014 So i will change the plugs, they do look awful, will only confirm what i have been telling my dad for over a year that it runs rich. In other news i just drove it, seems to drive just fine, transmission felt great (due to a fresh change of Amsoil MTG, firm believer now) and it warmed up just fine. The only thing that worried me was some steam started come out from under the hood when i got it home, im going to assume it just the spilled coolant from the initial burp, burning off. I think ill take sivlerton's advice and put 10w-30 next time. if it will help with pressure and such. Thanks again for all the help guys. -Kyle Link to comment Share on other sites More sharing options...
silverton Posted March 26, 2014 Share Posted March 26, 2014 (edited) As long as the needle doesn't drop to its off position while running, it's fine. Edited March 26, 2014 by silverton Link to comment Share on other sites More sharing options...
adamzan Posted March 26, 2014 Share Posted March 26, 2014 Is it an electric gauge or one with an oil line into the cab? On my grandfathers late 80s firebird it had ****** oil pressure but it turned out the sending unit was failing. Those plugs look like they have a huge gap! Link to comment Share on other sites More sharing options...
ferrariowner123 Posted March 26, 2014 Author Share Posted March 26, 2014 (edited) As long as the needle doesn't drop to its off position while running, it's fine. good to know, i really want to replace all of the gauges with some nice 52mm gauges, something more modern so i dont have to worry about it. Hopefully i get full ownership of the car when my pop's is sick of working on it, then i do everything i really want to do to it. (rotisserie, turbo, S13 rear, big brakes, oh the list goes on...( Is it an electric gauge or one with an oil line into the cab? On my grandfathers late 80s firebird it had ****** oil pressure but it turned out the sending unit was failing. Those plugs look like they have a huge gap! Its the originally factory unit, which has a history of not reading (at-least the coolant temp above it does) and it appears to be electrical, like i said, if i had my way, all of the gauges would be replaced with updated units... Thanks again for the help guys -Kyle EDIT: my dad installed the spark plugs, i seriously doubt he gaped them correctly (if at all), so when the plugs get replaced, ill changed them out, need to find out what i should get. Gap should be in the manual, somewhere. Edited March 26, 2014 by ferrariowner123 Link to comment Share on other sites More sharing options...
Alkorahil Posted March 29, 2014 Share Posted March 29, 2014 (edited) My two cents.......some is just me agreeing with others.... Change the oil and the filter. Get new plugs. 10-30w would be good weight oil for this older motor. Castrol has a good oil for older small engines that I have liked. I would stay away from blends or synthetic on this old motor. (just my opinion). Lower pressure at idle after warm up is not uncommon whent he oil gets old. low or no under load at 2K RPM is bad. If the pressure reacts as you increase and decrease engine RPM it is working fine. You could also have a bad oil pressure sending unit, though you typically tend to get insanely high pressure when one goes bad. Good job on getting the water valve repaired, I know we spent some time trying to find one last year. Edited March 29, 2014 by Alkorahil Link to comment Share on other sites More sharing options...
Alkorahil Posted March 29, 2014 Share Posted March 29, 2014 My Impretza is constantly belching white smoke (when ambient temp is low'ish) and my assumption is also because it is cat-less. Silverton!! fix your RS! Shame! shame! Link to comment Share on other sites More sharing options...
Precise1 Posted March 29, 2014 Share Posted March 29, 2014 Those plugs are nasty! Way too rich and/or oil burning. Is the black a hard coat or does a little wipe off/smear with a Q tip? B Link to comment Share on other sites More sharing options...
silverton Posted March 30, 2014 Share Posted March 30, 2014 Silverton!! fix your RS! Shame! shame! According to the State of Washington, nothing is wrong with it Link to comment Share on other sites More sharing options...
Precise1 Posted March 30, 2014 Share Posted March 30, 2014 Speaks volumes, doesn't it? B Link to comment Share on other sites More sharing options...
ferrariowner123 Posted April 1, 2014 Author Share Posted April 1, 2014 My two cents.......some is just me agreeing with others.... Change the oil and the filter. Get new plugs. 10-30w would be good weight oil for this older motor. Castrol has a good oil for older small engines that I have liked. I would stay away from blends or synthetic on this old motor. (just my opinion). Lower pressure at idle after warm up is not uncommon whent he oil gets old. low or no under load at 2K RPM is bad. If the pressure reacts as you increase and decrease engine RPM it is working fine. You could also have a bad oil pressure sending unit, though you typically tend to get insanely high pressure when one goes bad. Good job on getting the water valve repaired, I know we spent some time trying to find one last year. Thanks for the advice. I changed the oil to a new batch of 5w-30 and I think before our big rally. I'll get some new correctly gapped spark plugs and throw in some 10w-30 and keep that the new blend. I'm still not convinced on switching to conventional. Why would one want to on an engine that doesn't leak much (I over exaggerated the pan leak. It's negligible now.) And thanks. We finally gave up trying to Jerry rig something and after chasing our tail for over a year we bought all new everything. -Kyle Link to comment Share on other sites More sharing options...
ferrariowner123 Posted April 1, 2014 Author Share Posted April 1, 2014 Those plugs are nasty! Way too rich and/or oil burning. Is the black a hard coat or does a little wipe off/smear with a Q tip? B It will come right off. The car is definitely running rich. Has some sort of throttle body (not stock) and what appears to be new injectors. But it's not enough to convince my dad to do something about it. And I don't really think he'll let me do anything about it. -Kyle Link to comment Share on other sites More sharing options...
kdj Posted April 1, 2014 Share Posted April 1, 2014 So what goes on at the big rally? Link to comment Share on other sites More sharing options...
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