OK, I think that if the passages where blocked you would have noticed.
Maybe go back to the basics?
Thermostats? do they have 41mm of travel?
Recored radiator too small or 1/3 pass scheme compromised?
i got 2 different pair of thermostats, both from forum threads, all tested in the pan and has at least 42mm of travel and both sets was tested (just in case)
as i said, i have no trust in rad shop, not sure if they did a good work, only thing i did , i measured top and bottom hoses of radiator and saw 10C difference (on idle), im not sure if thats a sufficient cooling =/
1/3 scheme i only tested with screwdriver from the left bolt.
Of course i can get a new rad for 1000$, but thats quite a commitment given that im not 100% sure its radiator.
From your first post you made to your most recent I have suspected that your issue has been to do with the coolant flow either through a restricted passage, a thermostat issue, or more likely a radiator problem. You have stated that the rad has been recored and you have no confidence in the rad shop that did it…hmmmm…sounds like the smoking gun to me.
i wish! but how can i be sure? as i said new rad is $1k, wont be fun to get new rad and be at the same spot, is there some methods to check if its really not doint its job?
Thank you
While it’s running hot, spray water from a hose on the front of the radiator. Tell us if that helps. In addition you need a fan shroud for those electric fans. Finally I am not a huge fan of electric fans on vehicles not originally designed for them. The old mechanical fan , in addition to pulling air through the radiator, also pushed air over the engine all the time the engine is running which contributes to cooling the engine as well.
Good luck, stay with this list and collectively we will figure this out.
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Sure i will! Thanks
I understand, but fan clutches made me crazy, one was spinning harder/lighter then the other, no proper way to check them, i ended up with a collection of them and only then moved to efans, and i can confirm, it neither helped, neither made it worse.
Please also dont forget that i have no power above 3k rpm, shooting from tailpipe and weird small vibration i can only feel while sitting inside the car, and idle rpm hunting 20 rpm. not sure if its all related, but also a mystery , as i have checked everything.
P.S efan sitts on the custom made shroud, please see bellow
Ain’t at all hard to check a fan clutch. 1- Symptom (OPISITE You ) Overheat in traffic, cool with speed/flow. 2-Test- Car warm/ running- Jam a piece of cardboard into fan- clutch should have balls to shred same. As others said- if your fans both cycle on-off = bad. Are you at least wired so that one fan is on with Air Con.? Should be, and may provide simple avenue for testing. Are you running 180 deg. T Stats? I had good luck with replacing “average duty” Jag clutch with “big block Pontiac” unit at same time installed aftermarket metal clutch type racing fan from Jegs racing. Kept size same (17"?) so no need to re engineer shroud. May not be sexy for internet generation, but simple and proven. Good luck, again. Sadly- you may have mechanical trouble, but too many variables to confirm.
Hunting idle, no power and popping out the tailpipe and or intake could be a sign of a lean misfire, which hugely contributes to overheating.
Pull the vacuum line off the fuel pressure regulator on B (will cause full rich) and see if the symptoms improve.
Have you replaced the O2 sensors?
Thanks will do that test! No, i have a spare ones on a bench, im not changing it because of few reasons, 1) i had 2 faulty new items i bought, coil and fan clutch, almost got my car on fire with one bank not firing, so i have zero to none confidence in aftermarket parts 2) with o2 sensor failing, trip computer should show engine check code, isnt it?
i still have a little hope of air trapped in the system, i tried 5 different methods i found, but mb im still missing something? can someone give me a guide on how to make sure air is fully out?
Jack up front, 10" = great. Fill, run, pull plug top left- assuming you don’t have top cock. Shut down-top off, start- grab a smoke, repeat.
Get front left bleed point as highest point. Both caps off and bleed point open. Fill slowly in center point on crossover pipe till fluid seeps out bleed port. Reinstall bleed plug. Fill slowly, at center, more till overflow tank is three inches below cap point. Install that cap on expansion. More fluid slowly at center till 3 inches below. Cap. Run at 2000-3000 rpm for several minutes. Stop. Check at center cap only from now on. When cool. Always use center cap.
Opening the expansion tank cap causes loss of vacuum which allows recovery of fluid from overflow tank.
Everybody seems to have their own methods.
Mine that has worked ten times at least:
- Engine off
- Open both caps
- jack left front up about a foot
- remove bleed bolt at front/left
- fill reservoir tank until you can see coolant in neck
- cap it
- fill crossover until you see coolant from bleed bolt overflow
- screw in bleed bolt
- top off crossover pipe, squeeze upper radiator hoses to relieve air and continue to top off if needed, cap it.
- drive to operating temperature
- let sit a couple hours
- top off crossover (usually only about 12oz or less)
On both banks?
If the baffle is missing B bank will have lots of flow of uncooled coolant and A bank will have less flow with overcooled coolant.
A wrong replacement core that is too small and restrictive would have all the effects you describe.
There are also the Chinese aluminium rads that seem to work well, albeit with the need of some 'adjustments" but with a fraction on the cost.
Lots of info at the archives.
Does sound like lean running like Jeff and others said.
Do both exhausts pop?
I don’t know if the Marelli cars have the same ECU Base Fuel Map adjustment and Feedback monitor like the Lucas, but worth a try.
I had serious running issues when I fixed various vacuum leaks in mine that resulted in very lean running as the ECU was adjusted with a much lower vacuum.
From the Feedback Monitor you can also check if the oxygen sensors work as they should.
That said, if the Base Fuel Map is correctly adjusted the engine should work fine even with broken oxygen sensors as the ECU will automatically go to open loop and fuel according to the Base Fuel Map.
You can disconnect the oxygen sensors and see if the hunting is still there.
It’s also quite possible that your ECU has a problem.
As a crud test you could adjust the ECU richer to see if there is some difference.
Also, did you ever checked fuel pressure?
Good luck.
Last guy spot on in that busted O2 sensors = rich. Very happy we cleared that jack up 10" vs a foot. I’ll try 11" someday. I still go with the smoke break. Elephant in the room- rear crank sensor. They go bad- act as rev limiter. Fail hot, “reset” when cold. Up by / behind oil filter. Fault description was a bit vague, but check if that specifically fits fault.
Not necessarily so, it completely depends on how the ECU is setup.
I thought 0 O2 volts was signal for lean, and they fail low and to no volts (crack-old-break et cetera).
0v is rich, no oxygen to create voltage.
As I said, when the ECU detects a malfunctioning sensor it will go to open loop, i.e. no feedback, and will fuel according to the Base Fuel Map.
If you want to get an aluminum radiator, get from Wizard Cooling. Larger channels. Perfect fit
Thank you, never seen that one! will try it out
nope, on B bank - Bottom hose, i have only 2 thermocouples, i will try next time to see A bank as well
nope, B bank only
and today strange thing happened, so after inspecting both cats i have put them back, tried to unscrew O2 sensor on B bank cat, but couldnt, sprayed it with WD40, but it didnt help, i decided to try it later, was rushing to get back car back on the road for further testing, started the car, and as soon as it got to N temp, it started to pop on idle at B tailpipe, but not on acceleration as before, and wd40 was burning with smoke, engine o2 code was present and car didnt want to rev, as soon as wd40 burned away, it stopped and everything was fine at park. ok, i didnt drive the car, didnt have time, so mb problem would come back, but it gives me an indication that 02 sensor is quite sensitive ??
i dont have feedback monitor, as to my knowledge, what is that?
but here you gave me a good idea, let me explain, quite recently, i found out that map vacuum line rusted out near rear wheelarch, and was leaking vacuum badly!, i fixed that huge hole, pressure tested it, so all good now, but vacuum still at 16 on idle as before i found that leak (weird) . So your idea makes sense, but the car was overheating and not revving before and after leak was fixed.
both crank sensor replaced 4 days ago, nothing changed =/
Thank yo all for helping me out!
i will try several times coolant flash solutions, will see if it helps, fortunately i have transparent filters now on both banks, so i can see if any debris will be present
will try to replace o2 sensors, i have pair new (or will try disconnecting current ones as someone suggested firstly)
i also have spare ECU that i bought from ebay (just in case)
regarding radiator, unfortunately i live in Europe, so wizard cooling and other US radiators is not an option, i will probably go with radtec
Let me know if im missing something?
Can it be mareli ECU?