Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

2003 Altima Problems P0507 & Radiator the Cause?


I took my car to the local Nissan dealership because my a/c blows hot air and the SES light is on.

I received a call stating that it would cost $1600 to have my car repaired! Before I took it to Nissan, I pulled a code of P0507 (Idle Control System RPM Higher Than Expected) because my RPM’s rise & fall in park. The dealer stated all of my problems stem from a bad radiator (I can see the leak) and the radiator is throwing the P0507 code and is also the reason why my a/c is not working.

Does this sound correct?

How is the radiator related to the A/C and RPM problem?

The $1600 repair bill includes repairs for:

new radiator & hoses ($635+)

2 motor mounts ($600)

Idle relearn ($95)

Charging the A/C etc…

I’ve googled the code P0507 relating to Nissans and found conflicting information on how to resolve this problem. There seems to be a lot of misinformation on the topic and I just want my car repaired correctly the first time. I’ve had all of the recalls completed.

Any info is greatly appreciated! Thanks for your time :slight_smile:

I’m doubting the need for some of these repairs, like, the motor mounts; and, the prices are too high.
Save yourself a lot of money: go to an independent shop/mechanic. Some of the money you save, you could donate to your favorite charity. Your new mechanic could correctly diagnose the cause of the code P0507.

I’d almost hate to venture a guess on this one because a lot of this stuff is intertwined.
Normally an erratic idle is caused by a faulty Idle Air Valve or one in which the circuits are clogged up, but a vacuum leak could do the same thing.

As to the other stuff faulty mounts could allow excessive movement of the engine which can stress the radiator fittings due to the pushing and pulling of the hoses.
If you have faulty mounts you should have some vibration at idle and excessive movement of the engine when it’s revved.
If the A/C system is low then this means a significant refrigerant leak if it takes anything more than a partial can to top off.

There’s a lot of possibilities and unknowns here and I hate to even get into all of them but in regards to the leaking radiator has there been any overheating involved in this? Overheating will affect A/C operation and could possibly cause an idle problem.

I agree with you about needing all of these repairs… I also took your advice and picked up my car from the dealership and took it to an independent shop I found on this site that was recommended.

Here is a breakdown from the estimate of the Nissan dealership in Northwest Las Vegas:
Replace radiator assembly $675 factory or $550 aftermarket
Flush cooling system $95
Perform idle relearn & reflash as necessary $95
Replace A/C low pressure hose $325
Replace 2 engine mounts (bushings bad) $625
Flush engine oil system $129
Flush automatic transmission fluid $129

After all of these repairs, the service writer told me the engine idle problem may not be repaired because I could have a problem with the throttle body. Wow! He NEVER mentioned that yesterday! How is it possible for me to spend close to $2000 and not have the problem repaired? He said because the temp of the engine was off, he could not diagnose it properly.

The independent shop tells me I do not need a new A/C low pressure hose which contradicts the dealership it is not leaking) and is installing a new radiator with hoses, fixing the A/C (not sure what the real problem is but they are fixing it) and repairing the idle speed problem all for $890

At this point, I don’t know who to believe & I need my car in good running condition – it’s been 4 days without transportation. I’ve been dealing with these issues for months now and every person I take it to has a different opinion. Since I am female, maybe that is part of the problem. I do my research and try to understand these things, but it gets very frustrating! I gave in today and approved the repairs at the independent shop. Thanks for your help! I’ll keep you posted.

Keep your fingers crossed.