[neilm]

New to the forum….OK, first I am no mechanic. I recently bought a 2008 Outback with 170,000 miles. I was driving the car and it suddenly lurched, then lost power and began idling very rough. The ABS and another idiot light began blinking. A mechanic did a leak-down test and found the exhaust valve and guide in the #4 cylinder had broken and messed up the head, so he sent it out to be machined and repaired it. The head gasket had to be replaced also. The car ran fine for two weeks, then yesterday, I was driving about 70 mph when the car lurched, but didn't lose power. The same idiot lights came on but didn't blink and when I recranked it, they didn't come back on. The car ran fine with no over heating or loss of coolant. When I had the head work done, I replaced the radiator because it had a leak and I also replaced the front brakes. Would that have anything to do with the lurch and the idiot lights?

 

[eagleeye]

what lights? (there are so many.

VDC off light will light if any of the other lights come on, (fix the other problems, and that goes out).

what was flashing? -=cruise light? check engine light (flashing check engine is a misfire).

 

[neilm]

<style>*<!-- /* Font Definitions */ @font-face {font-family:"Times New Roman"; panose-1:0 2 2 6 3 5 4 5 2 3; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:50331648 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman";} table.MsoNormalTable {mso-style-parent:""; font-size:10.0pt; font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> </style> The first time, the check engine light, the ABS light as well as the ABS off light (the pictogram showing a car with squiggly lines coming from the back wheels) were all flashing. It was a P0304 code. This time, the two ABS lights came on but didn't blink. Then when I shut the engine down and recranked, they didn't come back on.

 

[gen2lover]

<style>*<!-- /* Font Definitions */ @font-face {font-family:"Times New Roman"; panose-1:0 2 2 6 3 5 4 5 2 3; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:50331648 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman";} table.MsoNormalTable {mso-style-parent:""; font-size:10.0pt; font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> </style> The first time, the check engine light, the ABS light as well as the ABS off light (the pictogram showing a car with squiggly lines coming from the back wheels) were all flashing. It was a P0304 code. This time, the two ABS lights came on but didn't blink. Then when I shut the engine down and recranked, they didn't come back on.

When you say the car lurched, I would imagine you mean it slowed down momentarily, correct?
It is possible you have a problem with a wheel speed sensor giving erroneous signals to the ABS module. You say you just had brakes done. Perhaps a wheel speed sensor wire or connector got disturbed?

 

[miker104]

P0304 is a misfire in cylinder 4. That was likely the cause of the lurching. When the check engine light comes on (due to the P0304 code) it sets the ABS/VDC and makes the cruise light flash to draw your attention to the code. Misfire codes generally make the check engine light flash as it can damage your catalytic converter due to unburned gasoline being sent to the cat.

 

[eagleeye]

<style>*<!-- /* Font Definitions */ @font-face {font-family:"Times New Roman"; panose-1:0 2 2 6 3 5 4 5 2 3; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:50331648 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman";} table.MsoNormalTable {mso-style-parent:""; font-size:10.0pt; font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> </style> The first time, the check engine light, the ABS light as well as the ABS off light (the pictogram showing a car with squiggly lines coming from the back wheels) were all flashing. It was a P0304 code. This time, the two ABS lights came on but didn't blink. Then when I shut the engine down and recranked, they didn't come back on.

car with the squiggly lines (slippery road) = VDC activation light.

which should not be doing anything on a dry road.

was this car ever in a wreck or off road, or have a bearing that was really really hot, such to damage a wheel speed sensor.

I guess the lurching caused by the engine misfire "could" jerk the car enough to make the VDC activate also.....but wow,...like the engine misfire is making the car drift of course of where you were steering.

 

[johnre]

.....but wow,...like the engine misfire is making the car drift of course of where you were steering.

Could be that if there are mismatched tires, they could also contribute to VDC activation when the engine misfires, especially in turns. A sudden change in wheel thrust would normally just result in a balanced change all around, but if one or more tires breaks grip earlier, that might cause VDC to try to intervene.

 

[eagleeye]

Could be that if there are mismatched tires, they could also contribute to VDC activation when the engine misfires, especially in turns. A sudden change in wheel thrust would normally just result in a balanced change all around, but if one or more tires breaks grip earlier, that might cause VDC to try to intervene.

another thought: when you got 3 tires with 35psi, and one with 19 psi.

 

[fisherella]

My thought when reading this was possible alternator?

Every time I've seen my ABS light it was during an alternator failure, which can also make the car lurch, the gauges and other things to generally go crazy. It might be something else still. I'm not a mechanic, just been driving a Subaru for about 5 years now.

 

[idosubaru]

Cylinder misfire: plugs, wires or swap COP.

Pull existing plug and inspect condition.

 

[neilm]

more problems

It was the wheel speed sensor. When they installed the new brakes, they left a loose wire. Thanks to everyone for the help

 

[eagleeye]

It was the wheel speed sensor. When they installed the new brakes, they left a loose wire. Thanks to everyone for the help

glad thats all it was and you did not trade it

straight up

as is

for a 1983 chevy malibu wagon.

 

[RoughDiamond]

Just for clarification (for future reference), when an ABS wheel speed sensor has gone bad (or disconnected), it will turn-on the ABS light, the VDC light, and on the newer models, the "Brake" light. This means the ABS and VDC systems are disabled (since they both rely on the wheel speed sensor to do their job).

However, are you sure it wasn't a C0304 code? An unplugged wheel speed sensor would not trip a P0304, nor would a P0304 be solved by reattaching a wheel speed sensor.