Follow up to post 53199 GU 4.2 getting hot

Submitted: Tuesday, Jan 29, 2008 at 15:24

ThreadID: 54000 Views:2362 Replies:3 FollowUps:8

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Member - Guy 59 (QLD)

Just thought I would post a follow up to my original post, have fitted an after market temp gauge as well as a EGT gauge, a hi flow thermostat and turned the bonnet scoop around to face backwards, thought it might help draw some hot air out of the engine bay. As Roachie (& probably others) have said in the past the Nissan temp gauge reaches "normal" (just below half way) at around 50 deg and stays there anything up to 100 deg, it doesn't start to move until the temp gets above 100 deg. Towing the caravan on the weekend , went up Cunningham's gap from the east at around 11 am sat outside temp around 30c , by keeping the EGT to around 450c was able to keep the water temp at 100c. the Nissan gauge didn't move from "normal". On the way home yesterday had 3 steep climbs in succession on loose gravel, again towing the van , outside temp 32c , we did it in 4WD low range 3rd, EGT was briefly at times up to 550c the water temp climbed to 105c the nissan gauge went up to 3/4 on the gauge.
Was able to keep it from getting any hotter by, when possible, just backing off the loud pedal a little to drop the EGT to between 450 - 500c.

In summary I'm glad I've fitted the water & EGT gauges , they let you know what is happening and you can adjust your driving to help keep the temp down. Hope this is of some help to others.

On another matter we also were able to take the off-road van off-road, was only for 6 km in total but low range 1st & 2nd, steep up/down with some tight turns , washouts & whoa boys, had no bottoming out issues, very happy so far. The van is a 17' Kedron ATV, single axle leaf sprung, GTM 1970KG.

Regards
Guy

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Reply By: desert - Tuesday, Jan 29, 2008 at 16:47

Tuesday, Jan 29, 2008 at 16:47

Good stuff. I'd like to know at what position you placed the senser unit for the other water gauge?

AnswerID: 284331

Follow Up By: Member - Guy 59 (QLD) - Tuesday, Jan 29, 2008 at 21:35

Tuesday, Jan 29, 2008 at 21:35

Gidday Desert, I put the temp sensor just below the bleeder that is on the thermostat housing.It is next to a factory sensor that I think is for the standard temp gauge.

Regards
Guy

FollowupID: 549147

Reply By: Trevor R (QLD) - Tuesday, Jan 29, 2008 at 20:32

Tuesday, Jan 29, 2008 at 20:32

Out of curiosity Guy, have you had the fuel pump and boost pressures played with. Reason I say this, lately I have been noticing very high EGT's (550+) when I am running boost pressures over about 9psi which in turn make water temps go sky high. I am wondering whether 9psi might be about the max you can squeeze out of the 4.2 and not adversly affect water temps. I have long gotten over worring too much when my water temps run even up to 118c, I figure if it was going to do any damage, it would have done so by now. Got 340000km on the clock now and I have been running into these temps consistently since the vehicle was new. When towing, I am lucky if the temps get under 100c usually closer to 105-110c.

Glad things have settled for you and I am sure the guages will do no harm, they do add plenty of info to give greater peace of mind.

Regards, Trevor.

AnswerID: 284369

Follow Up By: desert - Tuesday, Jan 29, 2008 at 21:04

Tuesday, Jan 29, 2008 at 21:04

Trevor, same question to you: Where have you located the sensor for the temp? As an aside, my 4.2 TD is running anywhere from 10 to 20 psi now for the last year or so on test. At these levels of boost I've seen the EGT's come down compared to when boost was set to 8psi max. I now control boost amount by lifting the right foot. However, water temps (standard dash gauge has not altered). I asume that the extra air being pushed in has helped lower the EGT's. It will go to 25psi if I let it, but I try to keep under 20psi when working hard. I must add that I have added a top mounted intercooler which further helped with lowering EGT's. Cheers.

FollowupID: 549133

Follow Up By: Member - Guy 59 (QLD) - Tuesday, Jan 29, 2008 at 21:56

Tuesday, Jan 29, 2008 at 21:56

Gidday Trevor R, maximum boost is 15psi and the pump was adjusted when the liquid to air inter cooler & Garrett B/B turbo was fitted.When not towing the water temp seems to stay around the 70-80c , did a test drive weekend before last up Mt Mee & Ocean View road was at midday and about 35c , EGT got to 500c & water temp 90c, so it seems to be mainly when towing that the temp climbs to a 100c +, understandably. Towing the van just down the highway not doing any notable climbing , EGT seems to sit at 300-400c and water temp sticks at about the 80-90c mark, which I'm pretty happy about, however it is comforting to know that the old 4.2 will withstand higher temps for sustained peroids of time if need be.

Regards,
Guy

FollowupID: 549151

Follow Up By: Trevor R (QLD) - Tuesday, Jan 29, 2008 at 22:02

Tuesday, Jan 29, 2008 at 22:02

desert,

Like Guy above, I have had my VDO temp sender unit mounted right beside factory temp sender.

Man you are running some serious boost there, I thought I was pushing the envelope at 14 max psi. I too have an i/cooler but mine is a Safari front mount unit. This has been on and off more times than I bear to admit in different efforts to keep the truck cool. Without the caravan things are fine but dump the van on the back and all hell breaks loose. Like you I just "control/monitor" all pressures/temps and egt's by altering the position of my right foot and just get the most out of it as I can. Can still blow off old petrol Pajero's uphill while I am towing (Hey Mark and Jo.....LOL!!) so I shouldn't complain too much hehehe.

Have you had your's on a dyno running full noise? I would like to see or know figures if you have. How many k's have you done with this boost running so high?

Cheers, Trevor.

FollowupID: 549153

Follow Up By: Trevor R (QLD) - Tuesday, Jan 29, 2008 at 22:06

Tuesday, Jan 29, 2008 at 22:06

Guy,

I get similar readouts to you when empty, problem is I am normally "loaded" so this all goes out the window quickly in this environment and accounts for nothing LOL!!!

Cheers, Trevor.

FollowupID: 549155

Follow Up By: desert - Wednesday, Jan 30, 2008 at 08:10

Wednesday, Jan 30, 2008 at 08:10

Trevor R, I havn't had any dyno work done since the boost went to 20psi. so can't help with any kw figures there, however at 11 psi, when last checked on dyno rear wheel kw was 97.6 pre intercooler. I'd only be guessing at the kilometres done at high boost, and I'd say around the 10k to 15k mark. I intend to have the turbo machined out and larger wheels fitted by MTQ then return to the same dyno to set fuel and check power then.

FollowupID: 549218

Reply By: Ozboc - Wednesday, Jan 30, 2008 at 06:58

Wednesday, Jan 30, 2008 at 06:58

have you got a photo of your setup with the gauges? - i have some trouble with temperature rising also - mainly on the big hills back from newcastle especially the BIG bridge on the F3 towing my 1250 KG + caravan and the gauge goes between half way and the end of the gauge - so i may consider what you have done also if its not to cluttering :)

AnswerID: 284452

Follow Up By: Member - Guy 59 (QLD) - Wednesday, Jan 30, 2008 at 09:14

Wednesday, Jan 30, 2008 at 09:14

Hi Ozboc, I'll see what I can do about a photo, in the mean time I'll try and explain the set up. I have a boost gauge(3" dia) that is cup mounted to the front door pillar, I have then mounted the temp & EGT gauges , both 2" with cups, to the cup of the boost gauge using a large stainless hose clamp. The cups have 2 slots in them that allows you to pass the hose clamp through them looks reasonable neat. Hope this make some sense, as I said I will see if I can send a photo.

See ya
Guy

FollowupID: 549239