My son in law’s Ford Fiesta died on him while driving on the highway. He said that it just died with no warning. I picked him up with my tow dolly. When I got to him, we tried to start it to drive it on to the trailer, and if memory serves me correctly, it tried to start but wouldn’t. I’m pretty sure that it had overheated.
When I had the opportunity to try to do some diagnosis of the problem, the starter turned the engine with no sound of compression. This is the 1.6l DHOC engine. Some sources say it is an interference engine others say it isn’t. My first thought was that given the mileage it must have jumped timing. I pulled the timing belt cover and confirmed that the cams were spinning. Good news and bad news, the belt didn’t jump timing. I was able to confirm alignment using both the crank alignment tool and verifying #1 at TDC by looking through the spark plug hole.
I ran a compression test and have no compression in any cylinder.
Pulled the valve cover and I don’t see any visible issues.
The only other options that I can see are blown head gasket, warped head or cracked head or block. But there is no sign of coolant in the oil. And it seems odd that there would be zero compression in any cylinder.
Any other ideas for me to look at before I pull the head? I was hoping not to make this a project!
Are the lobes of the #1 cyl. camshaft pointing up. 1e: valves closed ?
throttle wide open ?
I’ll have to look at the lobes. But they did spin when we checked compression, and they are in the correct relationship when at TDC.
What impact would the throttle body have?
The lobes pointing up means that the valves are closed.
Throttle BODY, no effect. The throttle valve needs to be fully open so that the cylinders can fill with air.
No compression on any cylinder is really strange.
Another thought, If the timing belt tensioner failed it could let the belt move a few teeth.
Oh, # one cylinder is the one closest to the timing gears/belt. Don't take offense, it has happened.
No compression on any cylinder is really weird for most failure modes other than slipped timing. Is the gauge even bouncing when cranking?
Broken Crank and / or broken cam.
Did you remove the cam cover or just confirm that the cam was spinning by looking at the cam gear?
Inspect cam make sure the whole thing is spinning.
I would then confirm that the pistons are moving in the cylinders. Bore scope or just a wooden dowel in teh plug hole and slowly spin the motor.
Thanks guys! Yeah it is really weird! That’s why I’m seeking your ideas.
I have removed the valve cover, and confirmed that both cams are intact and spinning as they should. Have also confirmed that all 4 pistons are moving.
The starter sounds like it is spinning with no resistance. In fact I first thought that it wasn’t engaging the flexplate. When I confirmed that the cams were turning, I assumed that it must have jumped timing. I was disappointed to find out that it hadn’t jumped time. I am assuming that it wouldn’t have jumped out of time, bent valves and then jumped back into time!
the compression tester, barely moves. Less than 1 psi and it holds at zero.
I agree that it is almost impossible for there to be no compression at all with a bad head gasket or a cracked or warped head.
I don’t want to pull the head until I’ve exhausted all the other possibilities. I’d hate to pull it then find out that I missed something obvious!
Tyler H said:
No compression on any cylinder is really weird for most failure modes other than slipped timing. Is the gauge even bouncing when cranking?
I have seen it a few times. If you really flood an engine you will lose all compression. Modern engines with low tension rings are bad for this. Add oil through the spark plug holes and crank it with the plugs out, usually gets it back enough to be able to start assuming that spark/fuel/timing are good.
The fun one was an engine that turned out to have broken its flexplate. The starter was turning the ring gear and the torque converter. That ended up being a flexplate, torque converter, and trans pump, because when the flexplate broke the converter broke its snout off and all sorts of bad happened.
In reply to Saron81 :
The battery had completely died by the time I got the car. No DTCs are showing.
In reply to Knurled. :
I’ll try some oil in the cylinders and see if that changes anything.
In reply to Sofa King :
That’s very odd.
I’d expect it to have cam/crank/sync codes if it was a timing issue.
Try a different compression gauge.
I would doubt the gauge, but when you turn the crank by hand with the plugs in, there is no resistance at any point in the compression cycle.
Knurled. said:
Tyler H said:
No compression on any cylinder is really weird for most failure modes other than slipped timing. Is the gauge even bouncing when cranking?
I have seen it a few times. If you really flood an engine you will lose all compression. Modern engines with low tension rings are bad for this. Add oil through the spark plug holes and crank it with the plugs out, usually gets it back enough to be able to start assuming that spark/fuel/timing are good.
The fun one was an engine that turned out to have broken its flexplate. The starter was turning the ring gear and the torque converter. That ended up being a flexplate, torque converter, and trans pump, because when the flexplate broke the converter broke its snout off and all sorts of bad happened.
Agreed at this point. If you put in some oil and nothing changes, I would expect that there are some really bad valve carnage, but you would expect to see some trace of that on the plugs.
I won’t get back to my shop until Wednesday, so I’ll try the oil then.
I agree that it seems like valve damage, but it appears to have not jumped time, so I Don’t think that there should have been another reason for them to be damaged.
Have you actually checked the timing or you assuming since the cams "spin" ?
Too many assumptions.
Sorry, I thought I made that clear in my original post. I did pull the timing covers and used the crank alignment tool to hold the crank in the TDC position, and confirmed that the timing marks on the cams were in the correct positions. And then I confirmed that the #1 piston was at TDC by looking through the spark plug hole. And also confirmed with a dowel rod. I also pulled the valve cover to confirm that the cams were both in one piece and in fact moving the visible portion of all the lifters and that all 4 pistons were moving when the crank was spun.
The only assumption that I am making is that it didn’t jump out of time....damage the valves.... and then jump back into perfect alignment!
As amazing as it seems, I once saw a 1600cc Fiat twin cam jump time and return to the marks while the car owner tried to start it. The belt slipped at the crankshaft pulley as near as we could determine, because both cams were correctly timed on first inspection. This failed at speed on the road.
Two things are coming to mind.
Weak fuel pump caused engine to run lean and melt the piston/ cylinder wall.
Engine filled with fluid and bent the valves or the rods.
Either way this is not looking good.
In reply to Donebrokeit :
I agree that it isn’t looking good!
pretty much anything that I can come up with, leads to pulling the head at the very least!
I’m just hoping for that last minute Hail Mary with something I’m missing!
iceracer said:
Throttle BODY, no effect. The throttle valve needs to be fully open so that the cylinders can fill with air.
Just thinking about this. I presume the Fiesta is DBW? I’ve never done a compression test on a DBW car, would you need to electronically open the throttle to get enough air into the engine for a compression test?
Still, the lack of rotating resistance makes me think Knurled is probably correct about the rings being the issue.
Rings don't suddenly fail, valves do.
Even if the rings are bad there still would be some compression.
You can’t believe everything you read on the internet.... but the list of interference vs non-interference engines shows this as a non-interference engine. Other places mention that it “might” be an interference engine. I really don’t know which is correct, but if it is non-interference, I don’t see how it would have damaged valves in every cylinder.
Donebrokeit said:
Two things are coming to mind.
Weak fuel pump caused engine to run lean and melt the piston/ cylinder wall.
Not likely at all. The engine doesn't make enough power to hurt itself like that. That is a super high compression or high boost turbo engine problem, and it generally happens when it is juuust not rich enough, but still making power. This engine probably runs stoich at WOT, until the ECM/PCM decides to start adding fuel so the converter doesn't melt down. The engine can take it.
