Discovery II Talk about the Land Rover Discovery II within.
Sponsored by:
Sponsored by:

P0304 and Overheating

Thread Tools
 
Search this Thread
 
Old Apr 1, 2018 | 09:04 PM
  #11  
number9's Avatar
Pro Wrench
Joined: Nov 2015
Posts: 1,935
Likes: 189
From: Coastal Georgia
Default

Originally Posted by jonjmill
the overheat is the effect.
The OH is is what will kill your engine.
.......
 
Reply
Old Apr 1, 2018 | 09:14 PM
  #12  
jonjmill's Avatar
Thread Starter
|
Overlanding
Joined: Mar 2018
Posts: 15
Likes: 0
Default

Originally Posted by number9
The OH is is what will kill your engine.
.......
So now that we have the obvious out of the way, when I can hook up a propper scanner to monitor the engine, what else should I be looking for that's going to help me get to the bottom of this?
 
Reply
Old Apr 1, 2018 | 10:11 PM
  #13  
LR03NJ's Avatar
TReK
Joined: Feb 2009
Posts: 2,186
Likes: 200
From: Linden, NJ
Default

I believe you issues are unrelated.
Replace the plug of the cylinder with misfire and go from there. If it get you by for days then its the plug. If not replace coils, wires and plugs all same time. That is a bad misfire.
As you mentioned you checked the cylinder and no signs of coolant, it also depends where the piston is located upon inspection after the engine cooled down. I just hope its not early stages of cracked block.
Or, I think you have another bad thermostat like mentioned above. Its more likely to have misfires when thermostat is broken and open all the time since the engine wont warm up completely. Cooling system is still a complete mystery to me. Tow of my discos have water fall sound each time you hit the gas but it never overheat. Other have tiny hole on top of the radiator and never overheat and the last have a tiny hole on top of the reservoir and still never overheat. But, when they have bad stuck thermostat, they will definitely overheat.
 
Reply
Old Apr 2, 2018 | 06:05 PM
  #14  
jonjmill's Avatar
Thread Starter
|
Overlanding
Joined: Mar 2018
Posts: 15
Likes: 0
Default

Originally Posted by LR03NJ
I believe you issues are unrelated.
Replace the plug of the cylinder with misfire and go from there. If it get you by for days then its the plug. If not replace coils, wires and plugs all same time. That is a bad misfire.
As you mentioned you checked the cylinder and no signs of coolant, it also depends where the piston is located upon inspection after the engine cooled down. I just hope its not early stages of cracked block.
Or, I think you have another bad thermostat like mentioned above. Its more likely to have misfires when thermostat is broken and open all the time since the engine wont warm up completely. Cooling system is still a complete mystery to me. Tow of my discos have water fall sound each time you hit the gas but it never overheat. Other have tiny hole on top of the radiator and never overheat and the last have a tiny hole on top of the reservoir and still never overheat. But, when they have bad stuck thermostat, they will definitely overheat.
I did try swapping the plug, so I can rule that out. I'm going to swap the wire over to the other side to see if the misfire moves with it. I hate just throwing parts at stuff to see if it fixes things.

Flushed the cooling system as well, and compared my new 180 tstat with the old one and when I run boiling water through them the new one is definitely outperforming the old. Hopefully that cures the over heat. I'll also have a propper scanner here tomorrow so I can monitor what's happening better.
 
Reply
Old Apr 3, 2018 | 06:46 PM
  #15  
jonjmill's Avatar
Thread Starter
|
Overlanding
Joined: Mar 2018
Posts: 15
Likes: 0
Default

Originally Posted by number9
First course of business is to get a UltraGauge or ScanGaugeII to be able to be able to accurately monitor your coolant temps.

Without real temp readings you are clueless and we are shooting in the dark giving temp advice.
......
Anything in particular I should monitor now that I have the ability to pull live data?
 
Reply
Old Apr 3, 2018 | 08:06 PM
  #16  
RoverJayTX's Avatar
6th Gear
Joined: Dec 2015
Posts: 6
Likes: 0
From: Dallas
Default

I had the exact same problem with mine. It was the head gasket.

They leaked so slowly that the steaming effect was minimal, really unnoticiable without the heads off to see all of them at once.

302, 304, and 303 and 305 all are close to the water jacket, it seeps in.

The Rover coolant level holds up well, but every few days it would burn off enough to cause a temp issue.

Top off and it is fine but repeats. Once I opened her up, they gasket was obvious.

One thing of note, my Rover was a beast. I did my hg at 200k, they were original gaskets. Feedback on the leak and causes were easy to spot with them.

A few misleading things happened in between my discovery of this. Intake heater and hoses failed, threw me off, a hose was old and busted, also threw me off, and my heater core failed, also threw me off.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
meels52
Discovery II
1
Oct 2, 2014 05:14 PM
kevinp661
Discovery II
10
Sep 30, 2014 05:23 PM
floundering
Discovery II
9
Jan 12, 2014 04:24 PM
Foe
Discovery II
0
Oct 3, 2009 08:34 PM




All times are GMT -5. The time now is 10:26 AM.