The highly anticipated results of the compression test on my range rover are in!
First, some background. I bought this car in January 2016 with 135k miles on it. The car had been sitting in a field in a field for the last 5 years and the history was largely unknown.
After about 2,000 miles of driving it throughout the summer of 2016 it was apparent that the car was in dire need of new head gaskets as all the familiar symptoms were there (sweet smelling white smokey exhaust, tell tale puddle under the engine, and even misfires under hard acceleration).
Not having any garage space at the time (October 2016), I asked a friend if I could park the car in her driveway while I worked. I anticipated 2-3 weekends to get everything done. I was very wrong. The whole process too about 6 weeks of free evenings and spare weekend days. I learned a lot along the way as there is not a ton of info available on the web, and forums are, well you know.
Anywho, I got everything back together and attempted to take it on a road trip to Cincinnati for thanksgiving but only made it 50 miles before a freeze plug blew out on the highway and I had to have it towed to a shop to be repaired. The shop replaced the freeze plug as well as another one that was looking questionable, then performed a leak down test (the engine overheated during the freeze plug blowout). Their consensus was that air was trapped in the system since I didn’t purge correctly after the head gasket repair. The air in the system caused the thermostat to close and the pressure to build up causing the freeze plugs to blow. The leakdown test was fine and they said the head gaskets were ok.
I drove it sparingly over the winter, never really trusting it to get me very far.
By springtime the familiar sweet exhaust smell was back and it was leaking coolant under the engine again (Range Rovers, amirite?). I was obviously frustrated, but couldn’t imagine that the headgaskets were bad again! I mean, I only put maybe 1,000 miles on the car all winter since the freeze plug incident.
Knowing that I needed to address the rust situation, I banished the car to a dirty garage in a questionable neighborhood so that I could really dig into it. It has been there since May and not started since then.
Last night, I decided to break out my compression tester and see what we were dealing with. So, without further ado, the results:
8 - 120
6 - 120
4 - 105
2 - 130
7 - 120
5 - 120
3 - 120
1 - 125
Soo, aside from #4 being a little low, everything looks to be in ok shape for a 138k mile engine with fresh gaskets. Honestly, the fitting was a little troublesome when I tested #4 so that could be what was throwing it off.
So why then are we getting coolant in the combustion? The coolant passages are on the ends of each head near #’s 8,2,7, and 1. When I installed the head studs, I did use a sealant on these outside studs, as the holes pass through the oil & coolant passages. However, the engine still had oil in it when I did this and I didn’t do the best job drying the holes out. My theory is that the sealant used on these studs has failed and is allowing coolant (and possibly oil) to penetrate into the outside cylinders. Of course the only way to confirm this is to take the heads off and try again. Obviously not high on my list of things to do considering I don’t even know if that’s where my issue is.
The next possibility is that the block is cracked or a liner has slipped. There were no slipped liners when I had the heads off, and I would think that either of these issues would present themselves in the compression test.
So, I’ve been ignoring this issue since the car was parked in May, but once I get this rust taken care of I’m gonna have to figure it out. Or else...