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I have a 00 ford ranger ohv 4.0, 144xxx miles. So every time I put it in drive it lopes out but when it’s in neutral or park it idles a little better, did a cylinder compression test and I have low compression on cylinder 4 which is causing it to misfire even though it’s getting spark and everything, I’m assuming a cracked head or something because I did have to put some more coolant in there a few weeks back and I’m hearing a pretty good ticking coming from the drivers side, checked all vacuum lines and they seem good although did find a yellow one coming from drivers side upper intake that is not plugged in, if anyone can help me with any ideas on what it might be before I tear the heads off I’m all ears and if you know where that vacuum line goes let me know, I’ll drop a picture, thank you!!
The lope is because engine has a load on it in gear, you don't feel a misfire on a V6 very much in Neutral/park because there is no load
Cracked head, or head gasket issue, would cause coolant overflow tank to bubble and engine to over heat, along with lost coolant
How low is "lower compression"
My 1994 with 300k still has 155psi
What was your difference between other 5 cylinders and #4
100psi would be too low
It says 140 psi in 4 but that’s what I was told by a local shop and I’m assuming they didn’t test it under load because I feel like it might make a difference? It doesn’t overheat at all, it also feels like I’m losing quite a bit of power, feels like it’s working hard to go up hills, I do have long travel on the front end so it does put more stress on the powersteering but I don’t know if that would have anything to do with it
You probably have the start of a leaking exhaust valve in #4, do they do a WET test, that would tell you if it Rings or valves that are losing the air
Compression is about 50% of static(non-running engine), when its running, so 140psi would be 70psi running which would cause less power generated and misfires but not full time
There should be a vacuum hose diagram on rad support, often color coded
I have a 00 ford ranger ohv 4.0, 144xxx miles. So every time I put it in drive it lopes out but when it’s in neutral or park it idles a little better, did a cylinder compression test and I have low compression on cylinder 4 which is causing it to misfire even though it’s getting spark and everything, I’m assuming a cracked head or something because I did have to put some more coolant in there a few weeks back and I’m hearing a pretty good ticking coming from the drivers side, checked all vacuum lines and they seem good although did find a yellow one coming from drivers side upper intake that is not plugged in, if anyone can help me with any ideas on what it might be before I tear the heads off I’m all ears and if you know where that vacuum line goes let me know, I’ll drop a picture, thank you!!
