Vacuum Solenoid Block

[fex]

Hi,

I was wondering if anyone could help. My turbo doesn't seem to spool up as quick as it should below 2k rpm. I have checked the actuator, it moves fine. I have replaced all of the vacuum lines. I have done the Mr Muscle turbo vane clean. I have checked that the actuator holds vacuum. The car has been remapped and EGR deleted (I removed the EGR components because I thought this may have been causing the problem). I haven't found a boost leak. I am just about ready to give up but:

I think I may have isolated the problem now though but I need someone to help me verify something:

If I connect a vacuum gauge between the vacuum solenoid block and the vacuum pump, I see a good 25Hg + of vacuum. This implies no vacuum leak(?)
If I connect a vacuum gauge between the vacuum solenoid block and the turbo actuator I do not really see past 17Hg of vacuum at idle. If I press the accelerator it may spike to 20 but immediately go down (like you would expect so that the vanes open turbo spools slower). I have read in many places that is healthy to see 20+Hg down the turbo actuator vacuum hose but everything seems so specific to each turbo that I don't really have a clue anymore.

Is this good enough to diagnose that the vacuum solenoid block is at fault? There are different variants of this block (6Q0906625). Mine is a 6Q0906625C (400434D). Does anyone know if they all do the same job? I phoned a Seat parts place and they said the part number has changed to G and quoted £195 for one brand new. There are quite a few on ebay but I was wondering if they all do the same job.

It is taking a long time for the problem to develop further and I am fed up with the reduced performance and MPG.

Many thanks

 

[Badger]

Have you been having these symptoms since the remap?

 

[fex]

Immediately after the remap things were brilliant, no problems then. I think this problem has taken time to develop and very slowly at that. I had it remapped last summer and I started noticing the problem in December so I don't think it is the map.

Really, I should look under the car and see where the actuator is extended to at 17Hg.

With the car switched off, I put a vacuum gauge between the vacuum solenoid block and the turbo actuator and pumped vacuum, and it was leaking. Should this happen?

 

[Badger]

I'm not sure TBH.

Do you have VCDS? Preferably Full?

 

[fex]

I don't have the full. I've been using 409.1.


Here are two images for a wide open throttle third gear pull and a general look of things:
imgur . com/0I5qLmY,qoukciF (unfortunately I can't link so please remove the space)



I don't think the graphs tell you much except boost is struggling to be controlled at times. It doesn't look a huge problem but it is giving virtually 10% of what it should be at low RPM. I can only think that the vanes aren't full closed.

I did have an idea of plugging the actuator at 25Hg of vacuum and seeing what happens throttle response wise but I can imagine this being very very bad for the turbo haha so definitely a no to that

 

[Badger]

Looked at the graph, do you have a log of the MAP duty cycle? I.e Group 11

It does look like it's over boosting by 2-300 mbar which isn't good.

 

[fex]

I guess the easiest thing for me to do is paste the data? The third gear pull begins at 26 (timestamp)

	Group A:	'011			
		Engine speed	Spec. intake press.	Actual intake press.	D.cycle MAP
	TIME	2850-3150			
Marker	STAMP	 /min	 mbar	 mbar	 %
0.4	2016.0	1213.8	1468.8	47.8
0.8	2037.0	1193.4	1468.8	47.8
1.1	2037.0	1193.4	1448.4	47.4
1.4	2058.0	1193.4	1438.2	47.4
1.7	2079.0	1254.6	1438.2	45.8
2.1	2100.0	1244.4	1458.6	46.2
2.4	2121.0	1234.2	1479.0	47.8
2.7	2142.0	1264.8	1479.0	57.8
3.1	2121.0	1040.4	1489.2	41.0
3.4	1743.0	1040.4	1336.2	55.8
3.7	1407.0	1071.0	1213.8	29.9
4.1	1386.0	1173.0	1173.0	31.5
4.4	1365.0	1203.6	1193.4	31.1
4.7	1386.0	1101.6	1213.8	32.3
5.0	1407.0	1122.0	1203.6	33.9
5.4	1407.0	1183.2	1213.8	31.9
5.7	1407.0	1132.2	1234.2	32.3
6.0	1428.0	1081.2	1234.2	37.1
6.4	1428.0	1091.4	1224.0	38.3
6.7	1449.0	1101.6	1234.2	38.3
7.1	1449.0	1111.8	1244.4	37.1
7.4	1470.0	1132.2	1254.6	35.9
7.8	1470.0	1193.4	1264.8	32.7
8.1	1491.0	1173.0	1285.2	39.0
8.5	1512.0	1183.2	1305.6	41.0
8.8	1512.0	1224.0	1326.0	40.6
9.2	1554.0	1224.0	1346.4	42.6
9.5	1554.0	1244.4	1366.8	43.8
9.9	1575.0	1203.6	1387.2	47.8
10.2	1596.0	1254.6	1397.4	46.6
10.5	1617.0	1275.0	1417.8	48.6
10.9	1638.0	1295.4	1438.2	51.4
11.2	1659.0	1285.2	1468.8	53.8
11.6	1680.0	1224.0	1458.6	55.8
11.9	1680.0	1264.8	1397.4	52.6
12.3	1680.0	1254.6	1387.2	51.8
12.6	1680.0	1264.8	1366.8	51.8
13.0	1680.0	1275.0	1366.8	51.8
13.3	1680.0	1275.0	1366.8	51.8
13.7	1701.0	1224.0	1356.6	54.6
14.0	1680.0	1183.2	1315.8	57.0
14.4	1680.0	1152.6	1295.4	40.2
14.7	1659.0	1142.4	1275.0	41.0
15.0	1659.0	1122.0	1264.8	41.8
15.4	1659.0	1101.6	1244.4	39.8
15.7	1617.0	1111.8	1234.2	39.8
16.1	1575.0	1111.8	1224.0	40.2
16.4	1575.0	1111.8	1224.0	40.2
16.8	1554.0	1152.6	1234.2	35.5
17.1	1554.0	1183.2	1244.4	33.9
17.5	1533.0	1173.0	1264.8	33.9
17.8	1533.0	1142.4	1275.0	36.3
18.1	1533.0	1152.6	1285.2	33.9
18.5	1533.0	1162.8	1285.2	33.5
18.8	1533.0	1213.8	1295.4	33.5
19.2	1533.0	1275.0	1315.8	38.6
19.5	1554.0	1315.8	1346.4	40.6
19.9	1575.0	1356.6	1387.2	44.2
20.2	1617.0	1438.2	1448.4	43.0
20.6	1638.0	1438.2	1530.0	48.6
20.9	1680.0	1438.2	1591.2	52.2
21.3	1722.0	1448.4	1621.8	56.2
21.6	1764.0	1458.6	1611.6	57.8
21.9	1806.0	1754.4	1601.4	47.4
22.3	1848.0	1927.8	1652.4	36.3
22.6	1953.0	2080.8	1836.0	49.4
23.0	2079.0	2111.4	2244.0	76.9
23.3	2205.0	2121.6	2080.8	57.8
23.7	2331.0	2131.8	2121.6	64.1
24.0	2478.0	2131.8	2254.2	72.1
24.4	2625.0	2131.8	2305.2	74.5
24.7	2772.0	2131.8	2305.2	75.3
25.1	2919.0	2131.8	2305.2	78.9
25.4	3045.0	2131.8	2284.8	80.5
25.8	3171.0	2131.8	2264.4	82.9
26.1	3297.0	2131.8	2244.0	85.3
26.4	3423.0	2131.8	2233.8	87.3
26.8	3549.0	2131.8	2264.4	91.2
27.1	3675.0	2131.8	2274.6	93.6
27.5	3822.0	2131.8	2274.6	94.4
27.8	3927.0	2131.8	2264.4	94.4
28.2	4053.0	2121.6	2223.6	94.4
28.5	4158.0	2080.8	2162.4	94.4
28.8	4179.0	1224.0	2111.4	94.4
29.2	3696.0	1193.4	1519.8	64.5
29.5	3024.0	2040.0	1224.0	59.0
29.8	3003.0	2131.8	1693.2	44.2
30.1	3045.0	2131.8	2356.2	76.1
30.5	3129.0	2131.8	2244.0	70.1
30.8	3066.0	1101.6	1856.4	60.2
31.1	3087.0	1111.8	1346.4	60.2
31.5	3003.0	1091.4	1193.4	59.8
31.8	2919.0	1081.2	1132.2	59.8
32.1	2835.0	1071.0	1101.6	59.8
32.4	2730.0	1071.0	1091.4	59.8
32.7	2625.0	1060.8	1081.2	59.8
33.1	2520.0	1040.4	1081.2	59.8
33.4	2436.0	1040.4	1071.0	59.8
33.7	2352.0	1040.4	1060.8	59.8
34.0	2247.0	1040.4	1060.8	59.8
34.4	2163.0	1040.4	1050.6	59.8
34.7	2079.0	1040.4	1050.6	59.8
35.0	2037.0	1040.4	1040.4	59.4
35.4	2016.0	1040.4	1030.2	59.0
35.7	1995.0	1040.4	1030.2	59.0
36.0	1974.0	1040.4	1030.2	59.0
36.3	1974.0	1040.4	1040.4	58.6
36.7	1953.0	1050.6	1050.6	32.3
37.0	1932.0	1132.2	1101.6	41.0
37.3	1953.0	1183.2	1173.0	47.8
37.6	1932.0	1193.4	1285.2	47.0
38.0	1932.0	1203.6	1366.8	45.8
38.3	1932.0	1193.4	1417.8	46.2
38.6	1932.0	1203.6	1458.6	46.2
39.0	1932.0	1203.6	1479.0	46.2
39.3	1932.0	1213.8	1499.4	44.6
39.6	1953.0	1244.4	1499.4	44.6
39.9	1953.0	1356.6	1519.8	57.0
40.3	1953.0	1856.4	1570.8	35.9
40.6	1995.0	2091.0	1744.2	19.9
40.9	2037.0	2101.2	2091.0	58.6
41.2	2079.0	2111.4	2244.0	67.3
41.6	2121.0	2111.4	2244.0	66.9
41.9	2184.0	2121.6	2244.0	68.9
42.3	2247.0	2131.8	2182.8	65.7
42.6	2310.0	2131.8	2182.8	68.1
42.9	2394.0	2131.8	2244.0	72.5
43.3	2436.0	2131.8	2254.2	74.1
43.6	2520.0	2131.8	2254.2	75.3
44.0	2583.0	2131.8	2244.0	76.9
44.3	2646.0	2131.8	2233.8	77.7
44.7	2688.0	2131.8	2213.4	78.1
45.0	2772.0	2131.8	2223.6	79.7
45.3	2814.0	2131.8	2213.4	80.5
45.7	2877.0	2131.8	2213.4	82.1
46.0	2940.0	2131.8	2203.2	83.3
46.4	2982.0	2131.8	2193.0	84.1
46.7	3045.0	2131.8	2182.8	84.9
47.1	3087.0	2131.8	2182.8	86.5
47.4	3129.0	2131.8	2172.6	86.9
47.7	3192.0	2131.8	2162.4	87.7
48.1	3255.0	2131.8	2162.4	88.9
48.4	3297.0	2131.8	2162.4	89.6
48.8	3339.0	2131.8	2162.4	90.4
49.1	3381.0	2131.8	2172.6	92.0
49.5	3423.0	2131.8	2203.2	94.0
49.8	3465.0	2131.8	2223.6	94.4
50.2	3507.0	2131.8	2254.2	94.4
50.5	3465.0	1183.2	2131.8	19.9
50.8	3444.0	1183.2	1428.0	63.0
51.2	3339.0	1162.8	1213.8	61.8
51.5	3234.0	1132.2	1142.4	61.4
51.9	3129.0	1111.8	1111.8	60.6
52.2	3003.0	1091.4	1101.6	59.8
52.6	2898.0	1081.2	1091.4	59.8
52.9	2793.0	1071.0	1091.4	59.8
53.3	2709.0	1060.8	1091.4	59.8
53.6	2625.0	1060.8	1081.2	59.8
54.0	2562.0	1050.6	1081.2	59.8
54.3	2520.0	1040.4	1081.2	59.8
54.7	2478.0	1040.4	1071.0	59.8
55.0	2436.0	1040.4	1071.0	59.8
55.4	2415.0	1040.4	1060.8	59.8
55.7	2373.0	1040.4	1060.8	59.8
56.1	2352.0	1040.4	1060.8	59.8
56.4	2310.0	1040.4	1060.8	59.8
56.8	2268.0	1050.6	1050.6	47.8
57.1	2247.0	1040.4	1071.0	59.8
57.5	2205.0	1071.0	1071.0	40.2
57.8	2184.0	1091.4	1111.8	43.0
58.2	2226.0	1254.6	1173.0	49.0
58.5	2142.0	1305.6	1315.8	46.6
58.9	2142.0	1346.4	1438.2	54.2
59.2	2142.0	1346.4	1540.2	59.8
59.6	2142.0	1305.6	1570.8	64.1
59.9	2121.0	1295.4	1509.6	63.0
60.3	2121.0	1295.4	1448.4	61.0
60.6	2121.0	1336.2	1407.6	59.8
61.0	2121.0	1377.0	1397.4	57.8
61.3	2121.0	1397.4	1397.4	58.2
61.7	2121.0	1366.8	1407.6	59.0
62.0	2142.0	1377.0	1397.4	59.0
62.4	2142.0	1417.8	1397.4	57.8
62.7	2121.0	1387.2	1397.4	58.2
63.1	2142.0	1366.8	1377.0	58.2
63.5	2142.0	1366.8	1346.4	56.2
63.8	2142.0	1346.4	1336.2	55.4
64.1	2142.0	1315.8	1315.8	54.6
64.5	2142.0	1295.4	1295.4	54.2
64.8	2121.0	1315.8	1285.2	53.4
65.2	2142.0	1346.4	1295.4	52.6
65.5	2121.0	1336.2	1315.8	53.4
65.9	2142.0	1356.6	1336.2	54.2
66.2	2142.0	1346.4	1346.4	55.0
66.5	2142.0	1305.6	1336.2	55.4
66.9	2142.0	1275.0	1315.8	55.4
67.2	2121.0	1264.8	1285.2	54.6
67.5	2121.0	1264.8	1264.8	53.4
67.8	2121.0	1275.0	1264.8	52.6
68.2	2121.0	1264.8	1254.6	52.6
68.5	2100.0	1264.8	1264.8	52.6
68.8	2100.0	1264.8	1254.6	52.2
69.1	2100.0	1275.0	1264.8	51.8
69.5	2079.0	1285.2	1264.8	51.4
69.8	2079.0	1285.2	1285.2	51.8
70.1	2079.0	1285.2	1285.2	52.6
70.5	2058.0	1295.4	1285.2	51.8
70.8	2058.0	1295.4	1295.4	51.8
71.1	2037.0	1295.4	1295.4	51.8
71.4	2037.0	1305.6	1295.4	51.4
71.8	2037.0	1224.0	1275.0	46.6
72.1	2016.0	1203.6	1275.0	47.8
72.4	1995.0	1162.8	1254.6	47.0
72.7	1974.0	1122.0	1234.2	43.4
73.0	1953.0	1091.4	1213.8	41.0
73.4	1953.0	1122.0	1203.6	42.2

 

[Badger]

Right, your duty cycle is way too high!

The safe level at WOT and 4000rpm is 80%

Your 94.4% shows that the ECU is opening the vanes to control the over boost.

This will be difficult but it will show if you have a vacuum leak. You need to be able to get under the car safely whilst the engine is running and get eyes on the turbo actuator and rod.

Run Basic Settings Group 11. This will cycle the actuator between 0-100% vacuum.

Your actuator should pull the rod all the way to the stopscrew at 0% and release all the way to the top at 100% I would check to see if the movement between 0-100% is smooth. When the actuator is at the stop screw, see if the rod stays solid or slowly creeps away which would indicate a vacuum leak.

 

[fex]

Or here is that data with the boost pressure times by a multiplying factor to scale it near the duty cycle %.



imgur .com/0QPjqiQ

 

[fex]

I have checked the actuator and against the spring resistance it is smooth, I've also replaced all the vacuum lines apart from the brake booster(?) ones and the big one that goes to the vacuum pump.

I don't have access to basic settings group 11, I really wish I did!

Should the actuator be at the stop screw at idle?

 

[Badger]

High duty cycle means the vanes are open.

It does look like you have a vacuum leak as the actuator is slowly opening at WOT.

Yes the actuator should be on, or very near the stop screw. Depends on the standard setup. Without basic setting 11, it would be difficult to tell whether it needs changing, but I highly doubt it.

 

[fex]

I have replaced all the hoses though, checked the actuator holds vacuum, and see that vacuum doesn't get past 17Hg down route of the turbo actuator hose at idle so it could very well be a leaking valve in the solenoid block?


But then I don't understand the data at idle, if there should be above 17Hg at idle then this would close the vanes further and it is already slightly over with 17Hg.

	0	903	1040.4	1060.8	24.7
	0.33	903	1040.4	1060.8	24.7
	0.68	903	1040.4	1060.8	24.7
	1.02	903	1040.4	1060.8	24.7
	1.35	903	1040.4	1060.8	24.7
	1.68	903	1040.4	1060.8	24.7
	2.03	903	1040.4	1060.8	24.7
	2.38	903	1040.4	1060.8	24.7
	2.72	903	1040.4	1060.8	24.7
	3.07	903	1040.4	1060.8	24.7
	3.41	903	1040.4	1060.8	24.7
	3.77	903	1040.4	1060.8	24.7
	4.11	903	1040.4	1060.8	24.7
	4.46	903	1040.4	1060.8	24.7
	4.8	945	1040.4	1060.8	24.7
	5.14	903	1040.4	1060.8	24.7
	5.49	903	1040.4	1060.8	24.7
	5.83	903	1040.4	1060.8	24.7
	6.19	903	1040.4	1060.8	24.7
	6.53	903	1040.4	1060.8	24.7
	6.88	903	1040.4	1060.8	24.7
	7.22	903	1040.4	1060.8	24.7
	7.57	903	1040.4	1060.8	24.7
	7.91	903	1040.4	1060.8	24.7

Thank you for your response by the way, what would you advise?

 

[Badger]

Unless the actuator is touching the stop screw, no matter how much vacuum you apply, the rod won't move any further. The percentage is only a representation of the actuator position not the amount of vacuum applied.

At idle, it appears to hold vacuum well and doesn't appear to fluctuate. As long as this is a log from the car at idle using the vacuum box.

 

[Badger]

Check this thread out for information. It's useful and will make you understand the issue a little better hopefully

http://uk-mkivs.net/topic/34834-vnt-tdi-turbo-how-to-adjust-actuator-cure-boost-problems/

 

[fex]

Ok I took a look I still don't understand something

If at WOT the duty cycle is at 94% does this mean the ECU saying please open the vanes I am generating too much boost?

And also you say that the actuator is slowly opening at WOT so there is probably a vacuum leak but if there were a vacuum leak surely the actuator would be holding less vacuum than it should so the vanes would be falling into the (fail safe) position of vanes open anyway which would create underboost? I think I'm missing something

What are the chances of the rod coming out of proper adjustment?

I have ordered a used vacuum block and after that I shall probably give up lol, again thanks for your help

 

[Badger]

Ok I took a look I still don't understand something

If at WOT the duty cycle is at 94% does this mean the ECU saying please open the vanes I am generating too much boost?

In short - yes

And also you say that the actuator is slowly opening at WOT so there is probably a vacuum leak but if there were a vacuum leak surely the actuator would be holding less vacuum than it should so the vanes would be falling into the (fail safe) position of vanes open anyway which would create underboost? I think I'm missing something.

It does look like a vacuum leak, however, it also looks more like sticky vanes. In the EDC15 ECU, 100% represents the vanes are fully open and 0% is closed. So in simple terms 0% is max vacuum and 100% in minimum/no vacuum. If you have checked the full movement of the rod, then it can't be this but \/

What are the chances of the rod coming out of proper adjustment?

Rare, but possible. If it has come out of alignment then the rod needs to be shortened massively to get the 80% @ 4000rpm you need.

I have ordered a used vacuum block and after that I shall probably give up lol, again thanks for your help

As above

 

[fex]

Ok, this is a muddle lol. Its probably not even worth jacking up the car tomorrow to see how far the actuator is from the stop screw.. I shall just wait eagerly for this other vacuum solenoid block to come. Last question then i'll give it a rest haha, do all of the variants of the vacuum block do the same job or are they specific? Maybe I should get a later one if they all do the same job

Cheers!

 

[Badger]

That I don't know

 

[fex]

I replaced the vacuum solenoid block and it didn't fix the situation. The whistle was very audible after changing. I don't know if this was just a coincidence or not. I have tried to get under the car and locate the whistle but everything else makes it very difficult to pinpoint it.

 

[fex]

Ok, I replaced the vacuum block with a used one off ebay. This vacuum block buzzes when the car shuts down. Things feel better sometimes but I am still getting overboost. I don't really know what to proceed with now

please see the boost log graph here:

imgur .com/oHaSrO4,salZT7q