CRD Max EGT?

[Rock Trol]

I just drove the Patrol up the Sturt Hwy to Callington and back. Its a 40 degree day here in Radelaide. Diving around town the EGT was between 200-300 degrees which is fine. On the flat (freeway) it can get up to around 400 degrees before dropping down to around 350.

Going up the big hill to the tunnel was interesting though. Fourth gear and car felt good but the EGT's got to 600 degrees (alarm sounded from the gauge) and I backed off a little. In no way was I pushing the car but it tended to sit between 550-600 on any of the long hills (5th or 4th gear no difference). On the flat its fine. Also coming off the ramp on to the freeway (flat) I had to give it a bit of stick so I could merge into traffic and again it hit the 600 degree mark.

The Patrol has a Cross Country Intercooler, 3 inch Exhaust and NADS so boost was always around 14.5-15 psi when under load. It has also had the ECU remapped. There was power there but I just felt I could not use it due to the EGT's.

This all happened with the Patrol empty and not towing. If I had the camper I think I would have had to go down to 3rd which defeats the purpose of the ECU remap (more power).

I have a couple of questions:
1. How much difference does the air temp have on EGT's? If it was a cooler day would it have been a lot better or only slightly.
2. What is the max EGT's that a CRD will tolerate. I get the feeling 600 is too low as it gets there very quickly. Or is there something wrong with the tune?

[the evil twin]

1 - In between IE better than slightly but not as much as a lot.

2a - Post turbo EGT depends on a lot of variables the answer could be between 500 and 700
2b - The rate of change of the combustion temp will have no relationship with the allowable peak combustion temp
2c - Tune is probably fine for performance and crap for towing or vice versa, only a Dyno will tell.

I reckon your boost is to low as well.

[threedogs]

low boost and position of your probe could be the problem.
The CRD can handle slightly higher temps too than a Di
A dyno may sort it out
Mego could tell you how high a CRD will go towing

[Maxhead]

I get 600+ when towing all the time and have now stopped worring about it. Matter of fact I might even disconnect the EGT gauge as it pisses me off!
I've seen that many Patrols rolling around Australia towing big rigs and totaly oblivious to any issues with them and totaly happy with the vehicle,

[the evil twin]

I get 600+ when towing all the time and have now stopped worring about it. Matter of fact I might even disconnect the EGT gauge as it pisses me off!
I've seen that many Patrols rolling around Australia towing big rigs and totaly oblivious to any issues with them and totaly happy with the vehicle,

Couldn't agree more...

[Rock Trol]

Thanks Nisshead. So it's not just mine.
As far as boost goes, what does yours run at. Mine runs at about 30 MAP or 15 psi max.

Ideally, what boost should be run when under load?

The EGT probe is just after the bend in the pipe behind the turbo.

The guy that tuned it said that 700 degrees would be the max for a CRD. Keep in mind that CRD's also inject fuel late into the combustion process to promote turbo spin so some of that heat has been added during the exhaust stroke rather than the main combustion stroke.

[kevin07]

ive gone close to 8 hundred but as was said lot of stockers towing pretty big stuff around don't seem to be having blown motor issues. but are having warped manifold issues which could be having an effect on your egts, mine did. also you could add a bigger scoop I did and lowered my egts only between 50 and a 100, but all helps.

[Rock Trol]

Thanks Kevin. My manifold had warped and broken a stud with the stock exhaust. Hopefully the 3 inch will keep it cool. Might set the alarm to 650 or 700 degrees C as it sounds more realistic than the 600. I have a larger intercooler with a 10 inch fan so I am confident that its getting air through there.

You won't need to worry about that anymore with the big V8 under the hood. Petrol as well so no EGT issues. Mmm...maybe I need to rethink a few things.

[the evil twin]

I'd set the alarm for 700 maybe even 750 and drive it to under 500 tooling around and 600-650 towing.

[Hodge]

I get 600+ when towing all the time and have now stopped worring about it. Matter of fact I might even disconnect the EGT gauge as it pisses me off!

I've been thinking about doing this for a long time. What you can't see won't hurt ya can it ? Then just drive the freakin' thing.

On topic...
Mines been 600+ before exhaust, EGR block, bigger IC and dyno tune and chip .Since then, I am yet to push it past 550C, and that was when I was really putting the foot down. I don't tow or anything to maybe thats why. But generally it sits 300-350 cruising, 400-ish on a incline or small hills.

[Rock Trol]

It was only on the big hills that it was going up to 600. This was just outside of Adelaide heading to Melbourne through the tunnel. It's in an area where a lot of trucks have lost brakes going the other way. Big hills that go for a long way.

When on flatish normal roads (heading north of Adelaide towards Port Augusta) or small undulating hills it keeps under 400 at 100kph. When the ECU upgrade was done last December I towed the camper up the same hills (without EGT gauge) and was able to keep it in 4th without problems. Before the tune and exhaust it would not hold 4th and I would do it in 3rd (55kph).

So maybe I don't actually have problem. It's just me freaking out at the temps on the gauge. I can still go up that hill in 3rd if need be when towing to keep EGT's down. Will be towing to the Riverland in a couple of weeks so will be interesting. Not many big hills but I will get a baseline on temps.

If I can get a little more boost what should I set it at? 18psi?

As a few have suggested on this thread, maybe we CRD owners need to chill out a bit and drive them without worrying. There's a lot of baggage linked to the ZD30 that's for sure.

[kevin07]

Thanks Kevin. My manifold had warped and broken a stud with the stock exhaust. Hopefully the 3 inch will keep it cool. Might set the alarm to 650 or 700 degrees C as it sounds more realistic than the 600. I have a larger intercooler with a 10 inch fan so I am confident that its getting air through there.

You won't need to worry about that anymore with the big V8 under the hood. Petrol as well so no EGT issues. Mmm...maybe I need to rethink a few things.
as et has said 750 should ok but not prolonged at this temp but tell me is your fan under your I/c or on top

[kevin07]

It was only on the big hills that it was going up to 600. This was just outside of Adelaide heading to Melbourne through the tunnel. It's in an area where a lot of trucks have lost brakes going the other way. Big hills that go for a long way.

When on flatish normal roads (heading north of Adelaide towards Port Augusta) or small undulating hills it keeps under 400 at 100kph. When the ECU upgrade was done last December I towed the camper up the same hills (without EGT gauge) and was able to keep it in 4th without problems. Before the tune and exhaust it would not hold 4th and I would do it in 3rd (55kph).

So maybe I don't actually have problem. It's just me freaking out at the temps on the gauge. I can still go up that hill in 3rd if need be when towing to keep EGT's down. Will be towing to the Riverland in a couple of weeks so will be interesting. Not many big hills but I will get a baseline on temps.

If I can get a little more boost what should I set it at? 18psi?

As a few have suggested on this thread, maybe we CRD owners need to chill out a bit and drive them without worrying. There's a lot of baggage linked to the ZD30 that's for sure.

when I was towing my camper up mt ousley nsw with the camper on 1.4 ton giving it a good kick I was at 18 psi boost and it was all good so I cant see why setting to 18 would be a problem

[Rock Trol]

Thanks Kevin. Fan is on the underside of the intercooler.
I will also adjust Dawes valve to allow a little more boost. Peaks at about 17-18 but settles down to just under 14-15 when under load and around 12 when cruising.

[Rock Trol]

I had a play with the Dawes valve after work and went for a drive north of Adelaide on the highway. I started off to a max of just over 19 psi and the car was going gang busters. Acceleration was great and EGT's where low. I thought I better lower it a tad though and have settled at 18 psi under heavy load (foot to floor) and around 16 under moderate load. When on the flat and at a steady speed the boost sits around 14psi. Yesterday it would peak just under 15 and sit on 12 when on a steady speed on flat ground.

Basically I have added 2-3 psi over what it was originally running. Car does feel good. Will have to drive up big will on weekend to get a feel of what it will do. Sitting at a steady speed on highway I was 300-350 degrees on the EGT gauge. That's 50 less than last time.
The only time I got near 600 was when I planted the foot to the ground in 4th gear and kept it there. This is not how I normally drive so not too worried.

Should I keep it at this boost (18psi max) or go a tad higher to 19 as I originally set it at?

[Rock Trol]

I have just returned from a run up the highway to Hahndorf (big hill) and the car ran a lot better and cooler than it did last Sunday. It was around 30 degrees (instead of 40 like last weekend) and the car kept to around 500 degrees. If I pushed a little harder I would get it to 550 and when I eased off it would drop under 500. The boost would vary between 16.4 and 16.9 depending on the situation. Last week boost was maxing out at the mid 14's under the same speeds and load. An increase of 2 psi has let the car run cooler and it felt faster as well.
Not sure how much the cooler weather played in this though.

Will be interesting to see how it runs with the camper behind it up the same hill. Having read a few threads on this forum and the other Patrol forum I feel confident that anywhere under 700 degrees is OK for a CRD. I will try and keep it under 600 if I can though. I do not think the ECU retune is making a big difference in EGT's as my temps are line ball with a lot of other CRD owners, even people with stock vehicles. It's only when I plant the foot to the floor that it starts getting hot quickly.

All in all, I am much happier with the higher boost this week than I was last week running lower boost.

[Patrol-Guy]

Got my GU serviced before my Lithgow trip last week and noticed the EGT's topping out at 600+ and boost only reaching 10psi. Stopped and changed it up to 19psi and going great.

Why the mechanic would drop the boost is beyond me. Probably the apprentice stuffing around. Anyway my EGT's were pretty good after that.

Also agree that too much attention is given to the ETG temps. I might change my alarm to 700deg also.

[MEGOMONSTER]

My temps were often getting 600-650. Not much difference towing or not.
My alarm is at 700.
I have alarmed once only, so I try not to get there.
I have now a 3" exhaust. Larger intercooler, larger scoop.
It has dropped temps between 50-80 degrees.
I now hardly ever see the 650 and I guess now peaks at 600ish.
The CRD has always been high EGT's especially after adding more and more to the vehicle, larger tyres the biggest culprit.
Still to fit Dawes to help with boost.

[Rock Trol]

Reading up on the CRD's and they deliberately run hotter as an aid to lower emissions. By injecting fuel late in the combustion cycle they heat up the gases so that the CAT can be more efficient at burning off the nasties. This is why they register higher temps than Di's. EGT is just not as accurate an indicator of what is happening inside the cylinder of a CRD compared to a Di. They can probably go over 700 deg safely but its probably a good self imposed limit we can use.

[the evil twin]

snip... EGT is just not as accurate an indicator of what is happening inside the cylinder of a CRD compared to a Di.

Post Turbo EGT readings aren't an accurate indicator of what is happening inside the cylinder of any internal combustion engine.
Pre Turbo is much, much better at giving an indication of cylinder combustion temperature which is what we are trying to control.

Most of us don't use pre Turbo because it is a harder install and we are lazy buggers so we just cop the inaccuracies of the variable temperature drops across the Turbo, probe placement, exhaust mods etc.

[Rock Trol]

I finally got a chance to tow the camper somewhere last weekend. A couple of mates and I went to Loveday and the weather was beautiful for the whole weekend. :thumbup:

The Patrol ran perfectly (can't say the same for my mates Prado) and exhaust temps on the highway where around 350 deg, raising to 400-450 on some of the bigger hills. Aircon was on all the time as the days where warm and muggy. When I was driving back to Adelaide I did manage to nudge 600 deg going up the hill just before Truro (long and steep). This bit of road gets you off the plains and into the Adelaide Hills heading towards the Barossa.

There is not much of a difference in EGT's when I am towing or not towing. Very pleased so far.