Hello there, sorry for my english and for a long post. I had to explain it...
I have problem with 1750 TBI engine. One month ago, I was on "preventive" service, to get car to right condition after buying it last year. Aslo there were some small issues with the car. One problem was with whining for 15minutes after start and some power loss after cold start.
The whining issue was common problem with steering. They cleaned up filter and replace burned liquid with Tutela GI/R. Now fixed.
The power loss issue was probably related to 2 flooded spark plugs with oil, on side of oild filling hole cap. When I bought the car it looks like someone spill out the oil around that area when filling it.
But the garage decided to take out head cover (over camshafts) and reseal it with engine silicone, we decided to do that to be sure that cover is not leaking. There was very small amount of silicone before. The engine looks too much coroded but they told me it can be caused by recomended long period of oil changes.
They also changed sparkplugs and cambelt with some trolleys. Oil was replaced by Selenia Sport Power 5W40. Dealer (Citroen) told me thay put in new oil, but it was some Castrol oil. I did 1000km on that oil without issues.
The car looks OK after that. But for alsmost 2 weeks I smell petrol inside cabin sometimes. After one pretty intensive I checked the engine and find out that oil filling cap was almost open. So I checked it and close it. After few days I have checked oild levels and cover again. There is a foam under cover. I know it can appear when drifing only trips but there is too much of it.
So I decided to go for intensive trip. I drove car agresively for 30km. Also I rev it up to 5000rpm few times. After that drive when I stop and let engine iddling it was like "scant of breath" runner. The revs didnt change too much, but soud was "hopping" pretty fast. Next day the car didn't want to keep running after ignition. So I kept it on throttle and drive very slowly around. Engine was running better and better after each 100m so I decide to go to work (10km trip). After that engine is running well. After few days I got error P0014 - "B Camshaft Position - Timing Over-Advanced or System Performance". Error appear again after a day when I clear it.
Also there is more oil than what was inside after service. They put all oil out, they let it leaking when working on other things and put in 5L. I read somewhere that the overal amount is 5.4L. So, I took out 0.5L from it, to see if the level is rising up. It looks stable now, the level is at 2/3 on the stick. But the oil is black, with mobile flash light it has green tint, I did just 300km after service. The water looks to be same whole time (from service till now). So I think that there can be only petrol, exhaust gasses or engine dirt (carbon) which can be released by different oil.
I'm going to this garage again after weekend. I want them to check spark plugs, check cylynder compression levels. Maybe I will force them to take out head (camshafts) cover and look inside again when they will not to do that.
So guys what can be the issue with the engine? Is there anything to get checked by them? I will be there for whole time, so I can take car about them, what they doing.
Some more pictures and more detailed are here
*** To not scare TBi users there is quick resume: ***
The issue has been pretty simple. The VVT solenoid filters has been jammed by dust. The oil level rised because the oil was missing in VVT. It was not contaminated.
The power issues was caused by limited oil flow througth VVT. When oil get into VVT wheels on higher revs it changed timing. But when revs dropped down the VVT was been still shifted because oil cannot be released, so engine had bad timing and got power loss.***