ISUZU Dmax Problems

[Paul Laycock]

I have owned the above for 12 years, diesel, 3 litre engine, in good condition, 158,000 Km.

The engine check symbol comes on after about 5km, temperature gauge goes to max point.

I have checked all fluid levels, belts etc and all seems to be normal.

All budding and ex mechanics, any idea on what the problem could be.

Only thing I can think of is perhaps gear box related, it's automatic but I seem to recall many years ago I topped up the gear box oil in an old Triumph Stag I once owned.

 

 

[Gibbs2]

Easy to check above, when running is the radiator header tank getting hot?

[brianinbangkok]

Take it in to a dealer NOW if it is really overheating your looking at major engine damage.
Chances are your waterpump broke.

[Paul Laycock]

Thanks guys, so thermostat, water pump and yes the radiator is getting too hot to touch, apparently someone will come to my house tomorrow.

I will suggest your opinions. Nearest ISUZU garage is 50km door to door so don't want to go that far. It's off the road so to speak until I get this sorted, then to ISUZU for any further diagnosis.

[Lancashirelad]

20 minutes ago, transam said:

Near nothing goes wrong with the water pump accept the bearing, if that fails you have water loss..

 

The engine stat controls water flow to achieve a constant temperature....

 

YOUR problem, FIRST, replace the stat, EASY....Top hose off, unbolt the alloy thingy on the engine, the stat is there...Take note of the temp reading on it then fling it over the wall...Spares shop, buy a stat the same temp range, fit, refill system with anti freeze/corrosion inhibitor, see what happens...

 

Perhaps better to take the old one with you to the shop to ensure its the right one ;-)

[brianinbangkok]

A seized up water pump does not always leak water. Had it on a Ford Ranger. No water loss. No leak. Stuck pump. Driving a car that overheats is a real bad idea.
Just saying do not drive it till problem is fixed.

When you start the cold engine does the temp. show low and how fast does it go up.

Swapping the thermostat is a good idea. Actually just take old one out and close it should also fix the overheating problem (as a test) but as its a cheap part just repace it

[lj cm]

8 hours ago, brianinbangkok said:

A seized up water pump does not always leak water. Had it on a Ford Ranger. No water loss. No leak. Stuck pump. Driving a car that overheats is a real bad idea.
Just saying do not drive it till problem is fixed.

When you start the cold engine does the temp. show low and how fast does it go up.

Swapping the thermostat is a good idea. Actually just take old one out and close it should also fix the overheating problem (as a test) but as its a cheap part just repace it

 

 

 

 

 

Good idea; try running it without thermostat.

[Gibbs2]

No problem running with no thermostat to check, easy to check if working just put it in a sausepan of water and heat up and see if it opens, too easy?

[Paul Laycock]

Ok, different advice, A guy is going to come and look at the car today. I think I will opt for the thermostat and see what happens. No way am I going to let anyone drive it. As you can tell I'm no mechanic so thanks for your input, I'll let you know the outcome.

[ClutchClark]

33 minutes ago, Gibbs2 said:

No problem running with no thermostat to check, easy to check if working just put it in a sausepan of water and heat up and see if it opens, too easy?

 

The old saucepan technique is far from accurate.

 

First you need to  closely monitor the temperature with a suspended thermometer and increase the temperature very very slowly. Furthermore, the t-stat needs to be prevented from making contact with the bottom or sides of the saucepan since those areas will be of a higher temperature than the water.

 

The fact is this vehicle is old enough that it would be very common for a failed t-stat so why not spend the 700 Baht and put in a genuine replacement part AND gasket (o-ring). It will need one soon enough anyway.

 

This issue could still be related to the water pump.

 

How often has the owner changed and flushed the coolant in the lifetime of the vehicle?

 

When you do refill this time do make sure to use the proper coolant because there are many many varieties available today and they are not all compatible with each other and can cause damage to aluminum, etc..

 

Best again to buy from dealer after doing a thorough flush. 

 

That truck ought to last you a lifetime. 

Edited August 8, 2016 by ClutchClark

[ClutchClark]

6 minutes ago, transam said:

BUT, you will not know at what temp it actually opens or closes....One can buy a stat that opens at what temp you want, the stats all look the same but can have a different temp range, that temp opening is stamped on the rim of a stat. You can buy a stat to fit with variations of l think 2 degree differences..I fitted a stat in my fun ride I think 6 degrees lower than stock to fix a problem..This guys stat may well open but at a very high temp.

 

Thats what I was trying to get at with my long winded post above.

 

Even a worn out t-stat will typicslly open at some point in hot water--but the critical thing is WHEN it opens.

[Gibbs2]

If the stat has failed it will never open.

[seedy]

Bickering posts removed.

[ClutchClark]

On August 9, 2016 at 8:17 AM, Gibbs2 said:

If the stat has failed it will never open.

 

A t-stat can fail in a couple of ways.

 

It can fail by not opening at all and it can fail by opening at temperatures volder than its rated at. 

 

Its the first one that can really good you up.

[Paul Laycock]

Sorry Guy's for the wait, as I said I'm no mechanic, it appears all it was a leaking water pipe. As I said I checked all fluid levels, looked in the radiator saw what I thought was coolant, wrong, it was nearly empty, it took nearly three litres to refill and seems to be fine now. Hose replaced.

[Dantekento]

I have some question about this 

My Isuzu Dmax 4JH1 have some problem

The engine light is on and when we check the code are p1335(a) engine speed circuit output malfunction 

What is the problem is that? I already change the crankshaft position sensor and nothing happen