All,

Approximately 2.5 weeks ago I had my Discovery 1 towed to a local LR independent shop after it stranded me post car wash. Essentially, after the wash I drove the car normally to a parking spot where I then proceeding to spend quite a bit of time cleaning and vacuuming the interior. I spent approximately 2 hours there. After finally finishing up I started the truck and it immediately started idling rough, but as some of you may know from my recent posts, this is a recent behavior that I was working on troubleshooting. I attempt to drive away from my space and when accelerating in first gear the truck hits a metaphorical wall at 1000 RPM. As soon as it hits 1000 RPM the engine starts missing heavily, stuttering, and shaking. I immediately stop, the truck continues to idle, albeit slightly rougher and after returning to the parking spot and looking for signs of water intrusion or a loose spark plug wire find nothing. I restart the engine. Same exact situation occurs. Luckily there is an AutoZone in the same parking complex, so I run over there, and rent a fuel pressure tester kit. At idle it is ~36 PSI which is sufficient. The engine is running like there is a massive vacuum leak, but no notable noises. No knocking, ticking, pinging, nothing. The truck is still running cool the entire time (monitored via an UltraGauge). The only noises are pops or crackles from the exhaust signifying the misfires and sputtering of the exhaust gases. I decide to limp it to my work parking lot so I can leave it overnight without it getting towed. The truck has enough power to accelerate to 1000 RPM in every gear, even up to fifth, so long as I don't attempt to rev higher it limps along. About 300 yards from my work the truck basically starts running so poorly that it cannot maintain forward momentum, even while in low range first gear. This is the point at which I had it towed (thank you roadside assistance).

I call the shop, which it was towed to next day, and explain the situation and ask them to diagnose. No word until I call them 3 days later, they state they have not been able to find the cause of the problem, but at first drove it around the block that morning with no issues. Then after parking and restarting were able to duplicate the behavior. They suspected a bad MAF sensor (I had recently replaced this, so I doubted this conclusion). Fast forward another couple business days. I call again. They say the MAF wasn't it and compression looks even across all of the passenger side cylinders. They say the are puzzled and even checked the clutch for issues. Nothing. I say okay, well let me know. Call about 4 business days later (this is at about 2 weeks). The guy says something along the lines of "to be honest man, I have set it aside for a little bit because I had to get some other work done. We have not found the problem and none of my guys have figured it out." He then lists a bunch of things they tried, from compression testing the cylinders, MAF swap, and a few others. I told him I understood, and let him know what I had done to troubleshoot. He said he would take a look again this week.

Now here is where it gets interesting... I call him back today after having not spoken with him for close to 5 business days. He told me this morning when his guy started the truck up that coolant came out of the tailpipe. Now I want to preface this with, I have no real reason to suspect the honesty of this shop or the guy I have been working with, but this is a big deal. He states that "the coolant is coming from the #6 cylinder, which is not near a water jacket on the head gasket so they suspect a cracked liner, which means a new engine." He also said the leakdown test looked fine and they could not find any other reason for coolant being in the system or how this behavior started in the first place.

I did some research on my own, and despite being a 96 GEMS apparently, cracked blocks behind the cylinder liners have happened and are more common than I thought. This could possibly concur with the sudden appearance of coolant out the tailpipe as well as the running issues. But it is odd since the truck just successfully made a 2300 mile round trip with no serious issues, despite the appearance of the strange idle and running rich towards the end. Hoping some of you who are more experienced can weigh in on this and help me decide... am I being rightfully skeptical, as in, I had no symptoms of this issue during the massive road trip (no overheats) and that it did not "dump coolant out the exhaust" until after being in the shop for 2.5 weeks (and they were testing the whole time)... or is this just the first stage of grief; denial...

 

Car goes haywire after getting wet.... I'd first look at the ECU. Water intrusion can do all sorts of strange things.

 

Definitely agree, but the only code present was for random misfires and no matter what the ECU does there should never be coolant coming out the tailpipe...

 

Unless you do the work yourself your alway getting taken.
is the shop trustworthy?
sounds like your heads were about to go you just didntt notice yet. I personally would want to see the coolant coming out the tail pipe. Either way they wont really know until they pull the heads.
all other bits could be a wet ECU like walt said - this has nothing to do with codes - this is water on circuit board issue.

 

You're not wrong there! Just a little shock considering the engine seemed to run great prior to this and like I mentioned above made it 2300 miles with no issues. Honestly, I don't know enough about the shop to call it one way or the other. This is my only dealing and it's the only Rover shop within 45 miles. They have lots of Rovers outside, including several Defenders so they get work.

Well maybe it was an ECU issue, but now with coolant bleeding out the exhaust it's definitely more than that.

How common is it for the D1 4.0 GEMS to crack a block? Wouldn't a head gasket failure be clear in a leak down or comprssioco check?

 

Id say your lucky this didnt crop up during that road trip!
Id have not heard of the D1's cracking blocks - I have heard of the D2's and slipped sleeves. but I am not the most knowledgeable one on here.
Can you post a link to what you found about the cracking?
Ive been to enough junk yards and every D1 was 175,000 or well over so they seem to last - Im guessing most were scrapped cause they needed a head job and they prolly got a price of 5k to do and just scrapped it.

If the shop deals with defenders they are prolly doing something right.

Im not an expert enough to know if a compression check would always detect a bad head gasket (but I thought it would). A leakdown is to determine where the compression is getting lost - that I do know.

 

I always start with the cheap and easy stuff first. Checking the ECU is free so that tops the list. I'm not claiming that I believe 100% it is the ECU, I'm just suggesting that is where I'd start.

As for the claim that 'coolant is coming out of the tailpipe', that sounds a bit far-fetched. Perhaps the exhaust has the strong smell of sweet coolant and that is what they are saying. In that case the first question is, "are you losing coolant?"

 

I'm with you I have never actually seen coolant pour out of a tail pipe. I am hoping they mean smell

 

I would think you would see bubbles in the reservoir tank when it is running if there is enough coolant to leak out the exhaust. that is a lot of pipe to fill before it comes out the back, and the exhaust heat would vaporize it too. Didn't say if the coolant level is dropping, a leakdown test should show if it is a head gasket or a cracked block but again, you should see bubbles in the coolant system.

If you are getting poor performance when the motor is cold, I would suspect a coil or wire problem, or ECU once they get hot enough to burn off the moisture, it may run ok. I would do more testing before condemning the block.. water out the exhaust on a cold start is not an indicator as a hot exhaust will get moisture from the air once it cools down. numerous dives where the motor never gets hot enough to dry out the system can build up water in the exhaust Happens in really cold weather when they add one of those auto-start units on a car that starts, warms up the car, then shuts off. I have thawed out numerous ice blocked pipes on cars that sat for long periods with one of those systems (we are talking sub-zero temps here) . just a possibility.

 

One thing I noticed with my recent CKP sensor repair, was that my idle is more even and the shift into gear "clunk" is gone - and in tune with your problem - (and I'll admit, I can't remember what all you've repaired lately) - My sensor was fine, but the harness wires to the sensor were cracked. A little water down the convoluted conduit could possibly alter the signal. I repaired my harness with cross-link insulated wire and a Nomex sleeve next to the manifold area - that area will never be a problem again. I seem to remember that it takes a bit to set a code, as in miles traveled, so you may not have limped around enough yet for that to show.

When my 96 slipped a liner, I was able to get a clue by looking at spark plugs - before I pulled the plenum and found piston ring pieces! Think positive - the relationship to a car wash (I killed a Jeep with that same technique!) and the sudden problem steer my thinking to the water intrusion theory. Good luck, Russ