Rising temp then returning to normal

[Cracker97]

Any help would be great.
I have posted a thread about this same issue before, but thought it was resolved. After a lot of work and money, I still on random occasions (manly when at low speeds, diff lock in) see a slow climb in temp to just under the upper white line. As I keep driving ( at same speed or load ) the temp will then drop straight back down to normal, below 1/2 way???

Work to date done by myself and mechanics includes,
New temp sensor
New alum radiator
New thermostat, 88 deg
New fan
New thermo fans on A/C
Engine flush
Valve replacement to repair engine miss
3 faulty injectors replaced
Vacuum advance unit replaced
Tuned
New 2.5" exhaust

After all this I still get an increased temp and fall, about to order a hi flow thermostat, as it only seems to occur under load.

Can anyone offer anymore clues on what to check next, or recommend a good mechanic to give a once over and test please.

Thanks in advance
Cracker

[jazzaD1]

slipped liner or cracked block maybe?
have you tried a different temperature gauge? the factory one isn't know for its reliability

[Judo]

Electrical? Maybe an earth problem. Only need a slightly poor connection and the resistance of the sender will appear different to the gauge.

[Kevin B]

I was going to suggest a Aftermarket Temp Guage as well, mine has the same problem, needle rose to almost 3/4 then back to normal, i put in a new aftermarket temp guage and while it still rises the guage only shows it going to 92deg max before it goes back to 88deg, another good investment is a Thermal (laser) Themometer, it gives a good indication of what various parts of your engine are doing.

[Cracker97]

Thanks
I have been thinking of a proper gauge for while.
I forgot to add Airtech snorkel as well to the list. I,m doing everything I can to get cool air in and hot out better. Hoping it saves a few litres of petrol as well and a couple of extra HP,s. Sounds bloody great but. Peter at Newcastle Muffler service sure knows how to improve the factories work....

Cracker

[Cracker97]

Has anyone added an Engine watchdog?? Are they worth the extra cost over the normal type of temp gauge.

[Cracker97]

Has anyone added an Engine watchdog?? Are they worth the extra cost over the normal type of temp gauge.

[SouthOz]

Ive fitted one of these. Very happy with it.

Engine Sensor Watchdog Overheating Temperature Gauge Alarm Relay Control Cooling | eBay (http://www.ebay.com.au/itm/ENGINE-SENSOR-WATCHDOG-OVERHEATING-TEMPERATURE-GAUGE-ALARM-RELAY-CONTROL-COOLING-/181233067339?pt=AU_Car_Parts_Accessories&hash=item2a3255254b&_uhb=1)

Dave

[Judo]

I fitted a VDO mechanical temp gauge. Sender is a straight swap without adapters. Just need to mount the 52mm gauge somewhere. Being mechanical it can't suffer from electrical issues.

[Tombie]

Water pump? Genuine? Recently replaced?

[Cracker97]

No, water pump is the only thing that remains as purchased. I,m fitting a mechanic gauge tomorrow and will do a beach run to record temps. If I see a 95 or over I,ll try the hi flow thermo , then I guess the pump is next.

Did I clean up of the earth today and cleaned the 2tabs for the temp sensor plug, slightly lower readings on gauge when I gave her a test run.

[Cracker97]

Purchased the new water temp gauge and inline adaptor to cut into top hose.
Cut in and installed, tested for leaks but gauge not yet wired up, need some advise from sparky at work.

Sat morning, drove disco into work (about 95km trip) no temp issues at all. Air temp was only about 7deg. After work our sparky showed me how to wire up gauge. Headed home towing a trailer , air temp about 35 deg now. 10 Kms into trip temp started to rise, got almost to top white line after about 50 Kms . Stopped to by drink and checked over the engine , water level in tank ok, cooled down motor, drove rest of trip home around 1/2 on temp gauge.

Late today I wired in new gauge, took truck for some hard runs up some hills, new gauge read upto about 100 deg and land rover gauge also started to rise???

I am thinking either stuck thermo or stuffed water pump??
I have been a bit suspect about the noise of the water pump for a week or so.

Also is it normal to have a small amount of blackish water drops come out the new exhaust on cold start up, and if you give her a bit of a rev. Once she warms up no more signs of moisture.

Any help would be great, worry about doing harm.

[biglandy]

Hey cracker97 dont know if this will help but just been reading out there that steam pockets cause this to happen? To fix it remove the bobble valve in the thermostat dont know if it will work,

[Cracker97]

Today I decided to change thermo to a hi flow, and replace the noisy water pump, after removing cover, found the thermostat jammed shut, pin had popped out and got stuck. after referring to the manual I believe the original one. Was installed back to front and I copied it.

After removing the belt, the pump was noisy, since then new hi flow installed and new water pump. I,ve been towing a fully loaded trailer thru traffic this afternoon, the land rover gauge stayed on 1/2 way, the new inline temp gauge shows the girl runs without load and cruising at top hose water temp of 92 c and when loaded up, in traffic stop start and getting up it up hills she climbs to 100 c. So happy to see some constant level on the gauge.

Still going to look into Mondao thermo fan idea I read on an old thread this morning. Makes sense to have fans covering the whole radiator, plus take fan load off engine. We did in race cars years ago...

[Roverlord off road spares]

Also is it normal to have a small amount of blackish water drops come out the new exhaust on cold start up, and if you give her a bit of a rev. Once she warms up no more signs of moisture.
.
yes it can be normal for condensation to come out the exhaust on a cold engine and if there is soot in the pipe it can make come out blackish.

When you replaced the radiator did you give the aircon condenser a good flush of water from inside to clean any dirt, mud ,dead insects, grass seeds etc out of the grid?. I was suprised how much stuff gets in there, it could also restreict airflow to the radiator.

[Judo]

Can't believe you could still drive with a fully closed thermostat! :eek: Sounds like you've nailed the problems now though. Those temps sound much better. Good one.

[Cracker97]

Did a couple of 9 mile beach runs today, 30+ deg! did one way running locked hi! next was locked low. LD gauge did go under the upper white line. In line new gauge got to about 108. At one point I did the condenser fans kick into high speed and both gauges dropped quickly.

Next week I have sparky booked to add over ride switch to dash to allow me to throw thermo,s on when I see increases.

I read old threads last night about temp increases based on auto box conditions or age. I am going to fully service box and see,,,,

[jazzaD1]

what type of coolant are you using, more specifically the glycol percentage?

[Cracker97]

It is Penrite coolant from the radiator place. Last check for elect level for alum rad had it sitting at 45%