Found source of engine shuddering.
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black g50
- Posts: 261
- Joined: Wed Nov 02, 2011 1:59 pm
- Car: 1994 Q45 Black/Black--235/40/18's avh3100 xplode 12" and amp 160000miles.2001 rodeo 190000miles
- Location: Middletown,De
Found source of engine shuddering.
My cooling system wasn't holding PRESSURE!Shop replaced both caps and test drove it and said they didn't notice shudder.Soooo,would anyone know why that would make a engine do that? Have noticed the electric fan hasn't came on,so I guess it's fixed.
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SanCarlosQ45
- Posts: 260
- Joined: Sun Feb 10, 2008 1:47 pm
- Car: 1994 Q45 144,000
2013 Nissan Xterra Pro-4x
1967 MGB GT Special - Location: Ooltewah, TN
Re: Found source of engine shuddering.
Did it shudder when the fan comes on or even before? If the fan is coming on then you are very close if not overheating. The shudder could be increased load on the alternator and the ecu compensating for the higher temp. It may adjust the timing and richen the fuel mixture to help cool things down. How was your fuel economy?
Re: Found source of engine shuddering.
Coolant temp sensor gets bad readings and/or the cold idle cam if there's air runing past it (if the caps were bad it would have leaked out coolant).
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black g50
- Posts: 261
- Joined: Wed Nov 02, 2011 1:59 pm
- Car: 1994 Q45 Black/Black--235/40/18's avh3100 xplode 12" and amp 160000miles.2001 rodeo 190000miles
- Location: Middletown,De
Re: Found source of engine shuddering.
It would shudder soon after open loop.Replaced MAF,pump and other sensors even thought bad cats.Gas miles were horrible,electric fan would come on if I let it idle for twenty min or highway driving.Sad thing is I ordered a new MAF that morning,makes (3rd.).SanCarlosQ45 wrote:Did it shudder when the fan comes on or even before? If the fan is coming on then you are very close if not overheating. The shudder could be increased load on the alternator and the ecu compensating for the higher temp. It may adjust the timing and richen the fuel mixture to help cool things down. How was your fuel economy?
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black g50
- Posts: 261
- Joined: Wed Nov 02, 2011 1:59 pm
- Car: 1994 Q45 Black/Black--235/40/18's avh3100 xplode 12" and amp 160000miles.2001 rodeo 190000miles
- Location: Middletown,De
Re: Found source of engine shuddering.
I had one of those caps with the red lever on it.Checked level every other day no noticeable loss,shop said it prob was going to over flow tank.If I ever felt suicidal all I had to do was stand behind car and inhale,now it's not as bad.Power somewhat has came back,feel more torque pulling me into seat......I guess this can be added to list of causes of engine shudders if Maf checks out.N/A Q45 wrote:Coolant temp sensor gets bad readings and/or the cold idle cam if there's air running past it (if the caps were bad it would have leaked out coolant).
Re: Found source of engine shuddering.
Well its always good to re-ground the mafs ground, as I have had my 240sx, past maxima and this Q45 run much better after adding grounds to everything aswell as every ecu ground.
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black g50
- Posts: 261
- Joined: Wed Nov 02, 2011 1:59 pm
- Car: 1994 Q45 Black/Black--235/40/18's avh3100 xplode 12" and amp 160000miles.2001 rodeo 190000miles
- Location: Middletown,De
Re: Found source of engine shuddering.
Thermostat replaced with oe,no more electric fan running.... 