What would you expect to pay for a water pump failure? A few hundred dollars right? How about over $4000?
We had a customer who was traveling from Iowa bring in a 2010 Lincoln MKS with only 78,400 miles and the 3.5 EcoBoost engine, stating he had a turbo problem according to the local ford dealer. We inspected and confirmed he had a broken shaft in the rear turbo. We ordered a turbo and when it came in proceeded to replace it and the oil line that feeds it due to some build up we couldn’t clean to our liking given how critical oiling is to a turbo.
Once the turbo was installed and the vehicle started we noticed it had a bit of a rough idle but otherwise ran OK. We connected the IDS (factory Ford scan tool) and started looking through the live data and found the timing appeared slightly off on one bank (side of the engine). It wasn’t bad enough for the computer to set any codes, but it just seemed off. I decided to take the car on a test drive to see if it ran OK before calling the customer to discuss the timing concern since we had encountered an EcoBoost F150 with a stretched chain and knew there had been some related service bulletins and this could be an early warning sign. When I first drove off it seemed to run fine but once I got out of traffic and could come up to highway speeds I rolled on the throttle to spool up the turbos and heard an odd noise similar to a belt but more like a bird so I let off the throttle. Everything sounded OK so I rolled on the throttle again and it seemed to spool up and then lag as if the wastegate had opened so I let off the throttle again. I turned around to head back to the shop and then randomly on acceleration would here a click or pop sound but it didn’t happen on deceleration so I pulled over and had the car towed back to the shop. With the timing problem in the back of my mind I was worried it might be trying to jump time and if it did could potentially do some valve damage and didn’t want to risk it.
Once back to the shop we got the vehicle back inside and raised it up to find the other (front) turbo shaft was broken as well. The big concern at this point was a potential oiling problem with the motor. Oil is critical to the turbo because of the high heat and speeds at which the turbine operates. Also the chain stretch issue in the truck EcoBoost motor is suspected as wear due to oil breakdown due to poor maintenance schedules. When discussing the situation with the customer he was pretty confident he had maintained the car very well and had purchased it new so he didn’t think maintenance should be a concern.
I was honest in the fact I didn’t really know what was going on at this point. I was struggling to put together how a car that had run great traveling cross-country until he got into town and then suddenly had two bad turbos and a timing problem, since neither should affect the other something must be linking them together, if the engine had an oiling problem then it could be affecting the variable valve timing system and throwing off the timing and it could certainly kill the turbos, so this was the likely path at this point so we decided we would pull off a valve cover and see how the inside of the engine looked, if there was a lot of varnish or sludge build up then maybe the maintenance was insufficient and it could be engine time, if the engine was clean then we could pull a few cam retaining caps and see if they were showing signs of oiling failure, and if the engine appeared healthy, work our way into the timing area to see if we could find the cause of the timing issue.
Once we had the valve cover off and found a clean engine which ruled out maintenance issues, my shop foreman took a long screwdriver and checked the water pump, which is driven by the timing chain in the transverse mounted EcoBoost (which is in the cars and SUV models) and found the bearing had failed. Just like that we had an answer to the timing problem, the slack from the bearing failure was causing the chain to have excess play between the camshafts which would cause one to be off.
So what about the turbo? could it be that the water pump was leaking coolant into the oil which could have caused insufficient lubrication to the turbos? It was the end of the day so we decided to put a pressure tested on the cooling system and go home for the evening. We knew if it leaked down overnight we could pull the oil drain plug and check for coolant and confirm the pump was leaking coolant into the engine. Oddly the water pump wasn’t noisy, most of the time when a bearing has failed you can hear a growling type noise when its spinning but this one, probably because of the oil from the timing chain, was silent.
I called to update the customer on our findings and the next steps and he then recalled that when he first got into town his heater had stopped heating briefly but then went to working again, which given all the data collected at this point, would indicate an air pocket in the cooling system as a result of the water pump leak. Unfortunately we hadn’t noticed the coolant low initially because the turbo has a coolant line going to it, and once removed, leaks out coolant so we topped off the coolant after replacing the turbo.
As suspected the following morning we confirmed the water pump was leaking into the oil, coolant in the oil lines would have easily boiled when it reached the turbos and provided no lubrication at all thus rapidly destroying them, and the timing issue was explained by the loose chain from the bad bearing in the water pump. Now it all made sense, we just had to repair the pump and second turbo, change the oil, and drive it to make sure everything else was OK.
Once the repairs were made the car was running great again. This was a complicated case to work through, which isn’t uncommon in our business, however you wouldn’t expect it on a car with less than 80,000 miles. It’s pretty disappointing that the water pump didn’t last longer, requires major disassembly of the timing chain to replace, and can do so much collateral damage.
I believe the fact it was on such a long trip contributed to the perfect storm of events, had this happened to a local car used for commuting the heater problem could have been the early warning sign to get the car some attention and maybe saved the turbos but with it happening between Iowa and Tennessee it served as a silent killer.
Sadly there isn’t much we can recommend to prevent this, I strongly recommend using a good synthetic oil on any turbocharged engine (except for the Mazda rotary engine) and keeping it changed every 5000 miles. Otherwise, if you have this engine keep a close eye on the temp gauge and heater performance, if one of them starts acting erratic I would get it checked ASAP.
Fortunately the F-150 engine is designed a bit different with the water pump being external and driven by a belt, instead there is just a sprocket on a bracket in place of the integrated water pump the car and SUV engines use. The F-150 however has its own timing chain issues which I will try to cover in another post since we have just completed another chain repair.