Bucking Disco and heat problem

[BlueDisco]

2001 Disco (67,000 miles) just started to run rough and buck as you try to accelerate. Hoping it is not a head gasket. Is this typical of the coil, wires? I re-gapped the plugs, but it still has the conditon.

Also have a problem when the vehicle is standing still the hot air does not blow from the heater. If I accelerate or drive at speed the heat works great. Coolant level seems OK and the temperature indicates normal.

[troverman]

As for the bucking problem, it is possible your air filter is blocked. Take all the hoses off before the throttle body (where the throttle and cruise control cables are) and make sure they are clear, and your air filter. (If you hold it up and can see slits of sunlight coming through it is probably ok) If this does nothing, then suspect the throttle position sensor (small black sensor connected behind the throttle body directly across from throttle / cruise cables) This sensor tells your engine to increase fuel as air is increased. To test it, remove the two 5.5mm bolts that hold it in place, and pull it out. (It slides off a small shaft) Leave it plugged in and start the engine. From under the hood, rev the engine using the throttle cable. If the engine acts no different than when the sensor is plugged in, there is a possibility this sensor is bad (about $100 part).

As for you heat issue, I have the same problem in our 1999 VW EuroVan. There is reasonably good heat if you are driving and the engine is revving, or if you are in neutral holding the engine to about 2-3000 RPM's for a minute or so. At idle, the air becomes ice cold or lukewarm. The coolant level is good, and the temp gauge stays fine. I replaced the thermostat in the van (very hard job) and it didn't fix it. Chances are you have either a water pump starting to go bad (only strong enough to push coolant through the heater core when revving), a blocked heater core (you can check by disconnecting one of the two hoses going side by side into the firewall on the passenger side, blow into one and coolant should come out the other disconnected end, this will be messy and do it only when the coolant is cold); or possibly air in the cooling system. Not sure where it is located, but there should be a bleeder screw on a hose somewhere you can bleed air from.


Best of luck.

[Disco Mike]

You need to get your codes read and get back to us with them..
As for the heater issuse, sound like you hav a air bubble trapped in the engine which should be bled out before you do damage to the engine.
Have you recently chsnged the coolant or have you had to add coolant?
Mike

[troverman]

Originally Posted by Disco Mike

You need to get your codes read and get back to us with them..
As for the heater issuse, sound like you hav a air bubble trapped in the engine which should be bled out before you do damage to the engine.
Have you recently chsnged the coolant or have you had to add coolant?
Mike

Although it would be a good idea to check for codes, if you have no SES light on and this issue has been happening for awhile, the cause of it may not be tripping a code. (The TPS may not trip a code, for example)