Bad Camshaft symptoms
- Thread starter turbows6
- Start date
That is exactly what it's doing. BLM's have been dropping (02's are up around .750-800 just cruising around). I used 10-30 Mobil One oil on the last oil change and 400 miles later it's doing this. The idle had sounded like bumpity-bump-bump, now at idle it's more like blub-blub-blub-blub and smells really rich. (yes fuel pressure is set right) Engine also doesn't seem as responsive, but cruises around just fine with no check engine.
BEATAV8
The Engine Whisperer
- Joined
- Feb 14, 2002
it's kind of tricky to positively identify a wiped out cam lobe without removing the valve covers and intake and then popping out each lifter for a look. But here are a couple of things you might want to check before tearing into it.
check the fuel pressure regulator. It might be bad, leaking fuel into the signal line and into the intake manifold. this would also make it hard to start when the engine is warm.
remove the oil filter and drain it out a bit. use a utility razor knife to cut it open about 1 inch down from the seal end (wear heavy gloves so you don't hurt yourself). Remove the filter can and look inside. You might see too many sparklies swishing around inside the can or caught in the filter pleats. That would indicate a cam lobe problem. Cam lobe material would be magnetic (iron) so you could check for that by using a magnet.
check the fuel pressure regulator. It might be bad, leaking fuel into the signal line and into the intake manifold. this would also make it hard to start when the engine is warm.
remove the oil filter and drain it out a bit. use a utility razor knife to cut it open about 1 inch down from the seal end (wear heavy gloves so you don't hurt yourself). Remove the filter can and look inside. You might see too many sparklies swishing around inside the can or caught in the filter pleats. That would indicate a cam lobe problem. Cam lobe material would be magnetic (iron) so you could check for that by using a magnet.
When lobe gets bad you'll start geting boost flutter above 12 psi.
Take valve cover off drivers side and check that #3 eq.valve is moving as much as others.
If you have a flat tappet cam i.m.h.o. mobil 1 is not a good choice.
I hope you just have a bad plug or something else thats a easy fix.
Take valve cover off drivers side and check that #3 eq.valve is moving as much as others.
If you have a flat tappet cam i.m.h.o. mobil 1 is not a good choice.
I hope you just have a bad plug or something else thats a easy fix.
bad cam
Mine was down on power thought it was a fouled plug, changed plugs no difference... did compression check low in 1-3 thought it was a blown HG took heads off not the HG....pulled lifter #2 EX concave waiting to get funds to get new camshaft.... can't afford roller would like to tho... But going with an erson cam... good luck
Mine was down on power thought it was a fouled plug, changed plugs no difference... did compression check low in 1-3 thought it was a blown HG took heads off not the HG....pulled lifter #2 EX concave waiting to get funds to get new camshaft.... can't afford roller would like to tho... But going with an erson cam... good luck
87Turbo-TWE4
Member
- Joined
- May 9, 2008
I use Mobil 1 10W-30 with ZDDP. Should I be using something else? 34,000 on the clock.
Pull valve covers off and crank engine over. All your intake rockers should move the same amount, and all your exhuast rockers should move the same amount. You can use a small ruler to measure the opening. I use a 6 inch machinist ruler and measure at the tip of the pushrod using the cylinder head as a reference.
pay attention to cyl 3
No synthetics on aftermarket flat tappet cams. its too slippery and cuases the lifter to stall in the bore. Once the lifter stops rotating.. the cam is done.
Especially with higher tension valve springs. Like 100'lbrs
You bought the best oil thinking it would be better, but this is not the case.
On a roller motor.. it is the way to go.
If the cam is wiped, you need to send the turbo to get rebuilt.
The fuel pressure doesn't have any issues (I have an autometer in-car gauge) The injectors are pretty new mototron 60#ers and it starts up just fine. Plugs look fine. Car was running and driving totally great, getting 26-27 mpg. Oil looks fine. Wasn't running hot and started showing problems during a time that I wasn't even getting the car into boost.
I'll pull the intake and check things out, no biggie.
Been looking for an excuse to switch to a roller cam anyway. How do you guys like the 210/215 cam that full throttle sells? lol
I'll pull the intake and check things out, no biggie.
Been looking for an excuse to switch to a roller cam anyway. How do you guys like the 210/215 cam that full throttle sells? lol
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
Dont pull the intake.
Pull the valve covers dude...follow Razors advice
Look at your vac signal what is it?
Does it flucuate at idle?
Pull the valve covers dude...follow Razors advice
Look at your vac signal what is it?
Does it flucuate at idle?
Ws6Stealthbird
Member
- Joined
- May 27, 2010
if a cam lobed is wiped, you would hear a top-end noise because the valve lash would be way out of adjustment.
3.8L V-8 eater
Well-Known Member
- Joined
- Jul 22, 2006
Funny to hear all these symptoms of a bad cam... I wiped out the #3 both exhaust and intake and the motor was run hard with none of the symptoms mentioned. Rock solid boost 23lbs., no noise, smooth on WOT, no knock... Had no idea how bad off the motor was until I went WOT from a dead stop and bent a push rod. After tear down it was evident the problem had been there some time. Just as Razor said take a close at #3 my lifter stopped rotating.. Was using Mobile 1 oil.
