R33 Gtr Vspec, With A Replaced Engine Issues

[Skysthelimit]

hi guys,

Hoping you can help me out with some queries.

2 months ago, my engine slipped a crank and resulted in me replacing the engine with another engine out of a R33 GTR Vspec with 70k.

I got the car back the other day, and I have found confusing temperature readings..

The Power FC shows the max temp it hits is 82 degrees, but on my dash, the temperature gauge it is high, hits the white line that is just before the max temp at the H. Coolant level seems fine, radiator fan spins. The oil temp seems fine from the stock gauge, sitting at around a third of the way to max. I have kept revs under 3.5k to keep things safe.

I am unsure which I should be trusting, whats the chances the Power FC is giving the wrong temp? I don't want to cook the engine that just got put in (I have it booked in at the end of the week).

Does the factory water temp gauge and the Power FC take temperature at different areas of the engine???

Also I have found the car to rev differently. When i release the clutch now, the revs drop to around 1700 rpm instead of down to idle. When stop at the lights, it might take about 20 seconds at 1700rpm before dropping down to the 950 idle. What can cause this, and is it something to worry about?

Thanks for any advice you can give me, much appreciated

[mad082]

the gauge sensor and the ecu sensors are right next to each other (well they are on the rb25, so i assume they would be on the 26 as well).

[Skysthelimit]

ok thanks, I'd assume the same, but will try to check into it.

..also another thing I have noticed is..

on start up, I get a very high knock sensor reading from the power fc of around 200.

after that, the knock sensor is fine, reads under 35. I would like to assume, its just picking up some noise in that frequency from normal start up sounds.. but the old engine never picked up any abnormal high numbers on start up.. what's the possibility of this high reading meaning damage is being done? is it a concern??

Cheers

[mad082]

the knock may just be cold engine noise, but it may also be something more serious. hard to say

[r32line]

Also I have found the car to rev differently. When i release the clutch now, the revs drop to around 1700 rpm instead of down to idle. When stop at the lights, it might take about 20 seconds at 1700rpm before dropping down to the 950 idle. What can cause this, and is it something to worry about?

Not a huge concern but the reason would be the way the Power FC has been programmed. A mate had a power FC put in his s15 and it did the exact same thing until he took it back and got it adjusted. Although I think in general, when you ahve a power FC and cold start the engine it tends to rev higher and for longer than a factory computer would. Talk to your tuner though.

As for the temperature issue I am not sure but playing it safe in the meantime like you said would be wise.

[Skysthelimit]

hmm cheers, thanks for the info r32line

.. I did wonder if it was a feature to keep revs up through gear changes.

[Skysthelimit]

..ok.. further to the over heating issue..

So I had the thermostat looked at by the workshop that put the engine in. seemed ok.. they removed it and made sure it was opening properly..

but still overheated.

so today they replaced the temp sensor that sits where coolant comes out of the engine.

but the engine is still reading max over heating on the gauge. I even changed the dash cluster with a friend's, to see if it was a faulty gauge, and it reads at the very top of H now

The coolant does not run hot, its not bubbling like it should be if the reading is that high.

Can this mean coolant coming out of the engine is running hot, meaning some sort of engine problem??

I'm trying to now track down who sold the workshop the engine to see what they will have to say about it.

Any advice? Cheers

[blind_elk]

There are 2 temp sensors just beside the thermostat housing - a single-pin sensor for the gauge in the dash, and a 2-pin sensor for the ECU. It sounds like your mechanic replaced the ECU sensor, you need to replace the gauge sensor.

The problem with the idle-down could be a dirty AAC valve - get it cleaned.

[Skysthelimit]

thanks for the info blind_elk, but I was actually there when he changed the sensor, he changed the single pin one that goes the the dash gauge..

which is weird why a brand new sensor made the gauge read even higher

I'm thinking I will change the ecu sensor too, cause I'm worried that's not reading correctly to the ecu

Edited December 11, 2011 by Skysthelimit

[blind_elk]

Then maybe the wire to the sensor is worn and earthing out (you can test a gauge / sensor malfunction by earthing the connection to the sensor - gauge will go full scale if it is working correctly). What does the gauge say when the engine is cold?

[boostn0199]

If your really worried maybe install another water gauge and see what that says.