a few more questions

[mva5142]

First want to thank the members here for all the help. you guys have a ton of knowledge and share it freely. That is great.

 

I have a 98 outback with 83k on the clock. I have noticed a couple things with it that I am not sure about.

 

1st, when it is cold and you lightly step on the gas, the rpms drop a few hundred before it catches up. Only does this when cold and only when you lightly step on the gas. If you step on it firmly, the rpms jump up and it goes like it should. Once it has run for a few minutes, it doesn't do it anymore. Doesn't even have to show temp on the guage for it to not do it. I'm thinking the throttle body might be dirty and something is sticking when it is cold and that lightly pressing shows it, but when you step on it, it doesn't give it a chance to stick? Not sure though.

 

Also, have noticed that when the heater is on and I step on the brake the blower motor slows down noticeably. As soon as I take my foot of the brake it blows fine. Happens in park, nuetral and drive. I have checked all the vacuum lines and none appear to be in bad shape and seem to be connected good. When you are driving it with the heater on and really step on it there is no drop in the blower motor which would indicate a vacuum leak. Not sure that the brakes are even tied in to the vacuum system, but what else would cause the blower to slow down? The rpms don't drop, so I don't think it is the load on the system, but I could be mistake.

 

Recent work inludes-head gaskets, timing belt, waterpump and all that stuff. The car had a bad head gasket when purchased (unknown to me) and only got to drive it about 100 miles before I had it fixed so I don't really know if it has always had these issues or not.

 

Any help or guidance would be much appreciated.

 

Thanks,

 

Matt

[kingbobdole]

  mva5142 said:

1st, when it is cold and you lightly step on the gas, the rpms drop a few hundred before it catches up. Only does this when cold and only when you lightly step on the gas. If you step on it firmly, the rpms jump up and it goes like it should. Once it has run for a few minutes, it doesn't do it anymore. Doesn't even have to show temp on the guage for it to not do it. I'm thinking the throttle body might be dirty and something is sticking when it is cold and that lightly pressing shows it, but when you step on it, it doesn't give it a chance to stick? Not sure though.

This could be a few things. Does it do it when it's "cold" like cold outside or just the engine's cold? Do you have a MAF or is it MAP only?

 

  mva5142 said:

Also, have noticed that when the heater is on and I step on the brake the blower motor slows down noticeably. As soon as I take my foot of the brake it blows fine. Happens in park, nuetral and drive. I have checked all the vacuum lines and none appear to be in bad shape and seem to be connected good. When you are driving it with the heater on and really step on it there is no drop in the blower motor which would indicate a vacuum leak. Not sure that the brakes are even tied in to the vacuum system, but what else would cause the blower to slow down? The rpms don't drop, so I don't think it is the load on the system, but I could be mistake.

The blower motor is not tied to the vacuum system, the brakes are... kinda. But either way vacuum doesn't have anything to do with this.

 

When you step on the brakes.... your brake lights come on, causing a load and a voltage drop across the system... that's what slows the blower motor.

 

The best way to "fix" this issue is to get some led type bulbs for the brake lights. They draw less current and cause less voltage drop. Otherwise that's pretty normal.