Jump to content
SAU Community

Recommended Posts

Hi Guys,

As thread title suggests I've got oil in my radiator.... Car is a '97 Stagea (RB25DET) converted to manual last year. Car doesn't miss a beat or run hot. Can take the radiator cap of and when it is running it doesn't blow bubbles or anything but their is defiantly oil from somewhere inside the radiator. Engine has done 155,000. Its not got heaps or anything.

Where do I start and what should i do?

Link to comment
https://www.sau.com.au/forums/topic/372125-oil-in-my-coolant/
Share on other sites

Might have a cracked head, its definitely a hard one to diagnose..

Theres also a coolant opperated oil coover on some nissans, not sure if your model has got one..

Anything that mixes coolant and oil could be the problem really...

I wouldn't say its a poorly serviced, radiator was flushed and new coolant went in 9,000k's ago so I doubt its that.

Simon how can I check if its the oil cooler assembly?

Its odd in the fact that oil is in the water but no water in the oil if that makes sense? eg. dipstick is just oil and when i did the oil and filter last week no water was in the oil :/

Have a few photos on my phone will upload soon

here are the photos apologies for the quality, iphone @ night isnt really that great....

The pics make it look alot better than it is.....

While I was out their i stuck my finger in the radiator and if u bend it around and feel the top of the tank its got a light layer of the oily gunk on the inside of it.... :-(

254649_2167486061754_1084756809_32540452_8035134_n.jpg

250267_2167486381762_1084756809_32540453_4687164_n.jpg

263231_2167486701770_1084756809_32540454_3606291_n.jpg

Update:

Today I got the car compression tested and TK tested (checksfor combustion gasses in the coolant).

Compression results were as follows: 1. 155 2. 160 3. 135 4. 145. 5. 160 6. 160.

TK test showed NO sign of combustion gasses in the coolant.

When I first dropped the car off and left they called within15 minutes asking for me to come back as they wanted me to show them what I wasworried about because at the time when they first pulled the cap of their wasno oil or anything around but by the time i walked back a little bit hadbubbled up. Mechanic assumes that the headgasket might be on the way out but it’sin its VERY early stages.

He suggested that I lower the boost (currently at 12psi) becausesometimes It hits fuel cut when you boot it (saying that this is very rare as Ibaby it mostly...) and that I just monitor the temperature and oil and coolantlevels.

Just after a couple more opinions on it, perhaps I shouldjust monitor it and keep my eye out for a wrecked stag and buy the donk....

Rough prices was $1500 for head gasket (metal) replacement aslong as my head is fine or worst case scenario $2500.

Thanks once again guys J

a bit strange you have no bubbling in the radiator and the combustion gas test came up negative.

Have you pressure tested the cooling system. i highly recommend this, its a check i do first when any car comes into work with a possible hg issue.

if you have a substantial pressure drop over a short period of time and theres no coolant running out on the ground you have a pretty good idea its going somewhere its not supposed to, like into the oil or into a cylinder!

pricing for headgasket job sounds fair enough, maybe go ahead and do it anyway if you plan on boosting the car more, that way you have a nice strong metal headgasket plus you rule out that being a problem.

Thanks for your input cam,

Yeah it is interesting it came up negative, but he did say that I've caught it VERY early and still suspects HG

I haven't pressure tested the cooling system no, theirs no milkshake in the oil or under the cap... yet

Yeah id do a metal head gasket but in saying that im running a stock turbo and you dont want to put more than 12psi through one of those with a ceramic wheel so is a metal HG really worth it

its worth fitting if you have a blown headgasket anyway, and if you plan on going bigger turbo down the track.

i suggest going back and asking them to pressure test the cooling system and go from there.

you dont have any power steer or transmission fluid cooling through the automatic radiator do you?? just checking as there might be a hole between the oil and coolant tubes and oils getting in the coolant that way.

its it auto?

commodores blow the auto trans warmer into the radiator quite frequently and it looks like you have a blown hg but its actually trans fluid = negative TK test

if you can, run an external cooler for a few days and see what happens

also, get them to drop some oil down the bores and re-do the comp test

and they should do a leakdown test too, that will tell you more info too

Update:

Today I got the car compression tested and TK tested (checksfor combustion gasses in the coolant).

Compression results were as follows: 1. 155 2. 160 3. 135 4. 145. 5. 160 6. 160.

TK test showed NO sign of combustion gasses in the coolant.

When I first dropped the car off and left they called within15 minutes asking for me to come back as they wanted me to show them what I wasworried about because at the time when they first pulled the cap of their wasno oil or anything around but by the time i walked back a little bit hadbubbled up. Mechanic assumes that the headgasket might be on the way out but it'sin its VERY early stages.

He suggested that I lower the boost (currently at 12psi) becausesometimes It hits fuel cut when you boot it (saying that this is very rare as Ibaby it mostly...) and that I just monitor the temperature and oil and coolantlevels.

Just after a couple more opinions on it, perhaps I shouldjust monitor it and keep my eye out for a wrecked stag and buy the donk....

Rough prices was $1500 for head gasket (metal) replacement aslong as my head is fine or worst case scenario $2500.

Thanks once again guys J

seriously could swap in a new stagea neo engine for 2500... including fitment. Simon is on the right trach with the heat exchanger too.

Yeah thats it, could put in another Stagea donk fairly cheap... But how do I know the replacement isn't shagged too?

How hard would it be to put a NEO into it seeing as it's a series one stagea whiche have the pre NEO rb25det

Pretty keen to get it happening as I dont like the idea of not being able to rely on my car...

post a pic as a poorly serviced car will get a rusty looking foam build up in the cap area.... its often mis diagnosed as head gasket.

I still think this is the most likely reason. Give the colling system a good flush and perhaps clean the radiator.

Other than some crap in the radiator, are there any signs of a blown hg?

loosing water?

water in oil?

loss of power /compression?

zorst in the water? (already ruled out).

Even if there is....if it is "midly blown" or "early", I would got straight for the chemiweld. Best case it fixes the problem for $10. Worst caase the motor is a bitch to clean for rebuilding....but as said above you would probably just start with a new one.

Hi Duncan,

Thanks for your wisdom :-)

Ill try and get another photo or 2 today and we'll see the difference from the other night.

In regards to other signs of a blown HG it hasn't shown loss of water or oil yet, but i'm assuming this is because I've caught it so early and the amount of oil is very minimal. But it does feel like it is lacking a bit of power but im not sure how much as I very rarely drive the car hard at all. As you can see it is down on compression between holes 3 and 4 perhaps this is where the leak is.....

I dont really want to put chemiweld or an additive like that into it truth be known.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Jdm DC2R is also nice for a FF car compared to the regular hatches of the time.
    • Gotta admit, I love the 20b Cosmo.
    • Now that the break-in period for both clutch and transmission is nearly over I'd like to give some tips before I forget about everything that happened, also for anyone searching up how to do this job in the future: You will need at least 6 ton jack stands at full extension. I would go as far as to say maybe consider 12 ton jack stands because the height of the transmission + the Harbor Freight hydraulic platform-style transmission jack was enough that it was an absolute PITA getting the transmission out from under the car and back in. The top edge of the bellhousing wants to contact the subframe and oil pan and if you're doing this on the floor forget about trying to lift this transmission off the ground and onto a transmission jack from under the car. Also do not try to use a scissor jack transmission lift. You have to rotate the damn thing in-place on the transmission jack which is hard enough with an adjustable platform and a transmission cradle that will mostly keep the transmission from rolling off the jack but on a scissor lift with a tiny non-adjustable platform? Forget it. Use penetrating oil on the driveshaft bolts. I highly recommend getting a thin 6 point combination (box end + open end) wrench for both the rear driveshaft and front driveshaft and a wrench extension. These bolts are on tight with very little space to work with and those two things together made a massive difference. Even a high torque impact wrench is just the wrong tool for the job here and didn't do what I needed it to do. If your starter bolts aren't seized in place for whatever reason you can in fact snake in a 3/8 inch ratchet + 6 point standard chrome socket up in there and "just" remove the bolts for the starter. Or at least I could. It is entirely by feel, you can barely fit it in, you can barely turn the stupid ratchet, but it is possible. Pull the front pipe/downpipe before you attempt to remove the transmission. In theory you don't have to, in practice just do it.  When pulling the transmission on the way out you don't have to undo all the bolts holding the rear driveshaft to the chassis like the center support bearing and the rear tunnel reinforcement bar but putting the transmission back in I highly recommend doing this because it will let you raise the transmission without constantly dealing with the driveshaft interfering in one way or another. I undid the bottom of the engine mount but I honestly don't know that it helped anything. If you do this make sure you put a towel on the back of the valve cover to keep the engine from smashing all the pipes on the firewall. Once the transmission has been pulled back far enough to clear the dowels you need to twist it in place clockwise if you're sitting behind the transmission. This will rotate the starter down towards the ground. The starter bump seems like it might clear if you twist the transmission the other way but it definitely won't. I have scraped the shit out of my transmission tunnel trying so learn from my mistake. You will need a center punch and an appropriate size drill bit and screw to pull the rear main seal. Then use vice grips and preferably a slide hammer attachment for those vice grips to yank the seal out. Do not let the drill or screw contact any part of the crank and clean the engine carefully after removing the seal to avoid getting metal fragments into the engine. I used a Slide Hammer and Bearing Puller Set, 5 Piece from Harbor Freight to pull the old pilot bearing. The "wet paper towel" trick sucked and just got dirty clutch water everywhere. Buy the tool or borrow it from a friend and save yourself the pain. It comes right out. Mine was very worn compared to the new one and it was starting to show cracks. Soak it in engine oil for a day in case yours has lost all of the oil to the plastic bag it comes in. You may be tempted to get the Nismo aftermarket pilot bearing but local mechanics have told me that they fail prematurely and if they do fail they do far more damage than a failed OEM pilot bushing. I mentioned this before but the Super Coppermix Twin clutch friction disks are in fact directional. The subtle coning of the fingers in both cases should be facing towards the center of the hub. So the coning on the rearmost disk closest to the pressure plate should go towards the engine, and the one closest to the flywheel should be flipped the other way. Otherwise when you torque down the pressure plate it will be warped and if you attempt to drive it like this it will make a very nasty grinding noise. Also, there is in fact an orientation to the washers for the pressure plate if you don't want to damage the anodizing. Rounded side of the washer faces the pressure plate. The flat side faces the bolt head. Pulling the transmission from the transfer case you need to be extremely careful with the shift cover plate. This part is discontinued. Try your best to avoid damaging the mating surfaces or breaking the pry points. I used a dead blow rubber hammer after removing the bolts to smack it sideways to slide it off the RTV the previous mechanic applied. I recommend using gasket dressing on the OEM paper gasket to try and keep the ATF from leaking out of that surface which seems to be a perpetual problem. Undoing the shifter rod end is an absolute PITA. Get a set of roll pin punches. Those are mandatory for this. Also I strongly, strongly recommend getting a palm nailer that will fit your roll pin punch. Also, put a clean (emphasis on clean) towel wrapped around the back end of the roll pin to keep it from shooting into the transfer case so you can spend a good hour or two with a magnet on a stick getting it out. Do not damage the shifter rod end either because those are discontinued as well. Do not use aftermarket flywheel bolts. Or if you do, make sure they are exactly the same dimensions as OEM before you go to install them. I have seen people mention that they got the wrong bolts and it meant having to do the job again. High torque impact wrench makes removal easy. I used some combination of a pry bar and flathead screwdriver to keep the flywheel from turning but consider just buying a proper flywheel lock instead. Just buy the OS Giken clutch alignment tool from RHDJapan. I hated the plastic alignment tool and you will never be confident this thing will work as intended. Don't forget to install the Nismo provided clutch fork boot. Otherwise it will make unearthly noises when you press the clutch pedal as it says on the little installation sheet in Japanese. Also, on both initial disassembly and assembly you must follow torque sequence for the pressure plate bolts. For some reason the Nismo directions tell you to put in the smaller 3 bolts last. I would not do this. Fully insert and thread those bolts to the end first, then tighten the other larger pressure plate bolts according to torque sequence. Then at the end you can also torque these 3 smaller bolts. Doing it the other way can cause these bolts to bind and the whole thing won't fit as it should. Hope this helps someone out there.
    • Every one has seemed to of have missed . . . . . . . The Mazda Cosmo . . . . . . what a MACHINE ! !
×
×
  • Create New...